Pro No Mo - I don't really need a MacBook Pro machine for hobby programming.

I’ve been trying to decide which Apple laptop to buy for hobby programming.

I’m leaning towards the cheapest laptop Apple sells, the 2019 MacBook Air. As far as I can tell, is fine for my current needs.

I specced out a more powerful and future-proof laptop, a 2019 MacBook Pro with 2x the RAM and SSD storage, but it was 60% more expensive.

I think it makes more sense for me to buy the cheaper laptop today, and plan on replacing it sooner. Especially because I have a lot of family members who would be fine with the cheaper laptop as a hand-me-down.

It does feel a little weird to decide that I don’t need a “Pro” machine. When it comes down to it, Xcode, a SSD and a retina display are all the “Pro” I need for hobby programming, and Apple has made those features available in the budget Air line.


In the end I bought the more expensive Macbook Pro. I am a sucker. :-)

The way I solved my daughter's "iMessage Activation" error

Writing these notes in case they help someone.

My daughter recently tried to add her Apple ID to her iPhone’sApple Messages app. (Settings > Messages > Send & Receive > Add Apple ID)

When she tried this, she got a dialog box where she could type in her Apple ID and password. After a 15 second delay she got an error dialog box:

iMessage Activation
  An error occurred during activation.
        Try again

She got a similar error message if she tried to activate FaceTime:

FaceTime Activation
  An error occurred during activation.
        Try again

I searched the Internet, and tried the various remedies that Apple and others suggested:

  • Reboot Phone.
  • Make sure the phone can receive SMS messages.
  • Enable/disable iMessage and FaceTime.
  • Log the iPhone out of iCloud and log back in again.
  • Visit and check the iCloud account to see if there’s any warnings or errors.
  • Update the phone OS to the latest release version of iOS.
  • Try to register with WiFi enabled but Cell disabled.
  • Wait 24 hours and try again.

Having exhausted the home remedies, I contacted Apple Support by phone. Apple Support listened sympathetically, and ran me through the same steps, it roughly the same order. They also did a little bit of checking on their own of the Apple ID account to see if there were any issues.

They couldn’t find anything wrong, and they suggested that I contact my carrier.

I contacted my carrier, T-Mobile, and they ran me through the same steps as Apple. They also had me check out my phone’s ability to connect to the Internet for Data and SMS. They had me turn off my phone for a minute, so they could update my phone’s SIM. Unfortunately, nothing they tried helped.

In the end, what worked was to admit defeat. I had my daughter create a new Apple ID. She was able to use the new Apple ID to log into iMessage without any problem.

So far the drawback of this solution seem to be:

  • My daughter lost everything she had stored in iCloud.
    • For many people this would be a serious issue.
    • Luckily my daughter does not use iCloud at all.
    • She uses Google services, like gmail, Google Docs and Google Photos, that do not depend on iCloud.
  • My daughter has to re-add all her Contacts to her new Apple ID.
  • My daughter lost some game progress in some of her Game Center aware video games.

My guess is that the problem was on Apple’s end. The symptoms and cure seem to indicate that my daughter’s old Apple ID account was messed up in some small way, and Apple’s diagnostic systems were not detailed enough to detect or correct the issue.

So, anyway, I wrote this up to offer one more home remedy for people suffering from the “An error occurred during activation” message when trying to log in to iMessage. That message could have one of a number of different causes. If you are seeing it, please try the simpler remedies first, and please contact Apple Support (and your phone carrier’s support) for help. But if everything else fails, be aware that for some users such as my daughter, one solution was to switch to a new Apple ID.

2018 iPad Pro 12.9" Report

After weeks of research and thought, I bought a iPad Pro 12.9” 3rd Generation.

My impressions, based on a week’s use:

  • It’s too expensive, especially once you include the pencil and keyboard case.
  • It’s a significant improvement over the 1st generation iPad Pro 12.9”.
    • It’s physically much smaller.
    • The new keyboard is nicer.
    • The new pencil’s magnetic charger makes it much more useful than before, because now it’s always charged when I want to use it.
  • Flaws
    • The magnets holding the pencil to the iPad are too weak. It’s easy to knock the pencil off the edge of the iPad when picking it up or carrying it.
    • When the keyboard case is folded back, your hands touch the keys. This feels weird at first.
    • The hardware is held back by iOS 12 and Apple App Store limitations.

FWIW I think for most people the ordinary 2018 iPad, with a Logitech Crayon, would be a better purchase.

But I do enjoy using it!

Solving the anemone puzzle in Botanicula

Botanicula is a whimsical graphical adventure game for the iPad and other computers. One of the puzzles near the end of the game requires a bit of thinking to solve. When I came upon it, after a couple of hours of play, I was too tired to think. So I wrote some code to brute-force the solution. I’m unreasonably pleased that it worked the first time. Here’s the code, cleaned up and commented:

// Solve the anemone Botanicula puzzle.
// Number the anenome 1 to 7, left-to-right.
// Encode a list of anemones into a single integer, where bit 0 is anemone 1, etc.
func encode(_ d:[Int])->Int {
	return d.reduce(0, {x, y in x | (1 << (y-1)) })

// A list of which anemones are pulled down when a given anemone is tapped.
let moves = [
	encode([5,7]), // Tap anemone 1
	encode([1]), // Tap anemone 7

// Calculate the effect of tapping a given anemone |m|.
func move(state: Int, tap m: Int)->Int {
	return (state | // original state
		encode([m])) & // raise the item that was tapped
		~moves[m-1] // lower the items that need to be lowered

// Brute force solver. Try all moves to depth |depth|.
func solve(state: Int, goal: Int, depth:Int) -> [Int]? {
	if state == goal {
		return [] // We've reached our goal, don't have to make any moves.
	if depth <= 0 {
		return nil // Ran out of depth, give up.
	for m in 1...7 {
		let newState = move(state:state, tap:m)
		if let soln = solve(state:newState, goal:goal, depth:depth-1) {
			// If we could solve the newState, prepend our move to that solution.
			return [m] + soln
	// Couldn't find a solution.
	return nil

// Produce the shortest solution, if one exists.
func tryToSolve(state:Int, goal:Int, depth:Int)-> [Int]? {
	// Do a breadth first search by searching successively deeper.
	for d in 0...depth {
		if let soln = solve(state:state, goal:goal, depth:d) {
			return soln
	return nil

let start = encode([1,6]) // This will vary depending upon the state of the puzzle.
let goal = encode([7]) // This is the desired state (just anenome 7 raised.)
let solution = tryToSolve(state:start, goal:goal, depth:12)

print(solution ?? "no solution found")

Computer History Museum Oral Histories

The Computer History Museum Oral Histories are a wonderful project. They are deep, long, interviews with many different programmers. Lots of never-before-made-public details about important projects.

For example, this oral history by Oral History of Kenneth Kocienda and Richard Williamson goes into details of how iOS was designed:

Oral History Video Part 1

Oral History Video Part 2

Or if you prefer PDFs:

Oral History Part 1

Oral History Part 2

One of the interesting things I found out was that there was an attempt to use HTML/Web APIs to write iPhone apps, and that for the first two or three iOS releases some of the apps, including the Stocks and Weather apps were implemented as HTML/Web apps.

Trying to decide what personal computer to buy in 2018

I’m thinking of buying a new personal computer. I’m writing this essay to crystalize my thoughts on what to buy.

Why I don’t currently have a personal computer:

I must have bought twenty personal computers over the years, starting from an Exidy Sorcerer in 1978 and ending with a 13” Macbook Pro in 2013.

But since 2014 I’ve been without a personal computer of my own. The Macbook Pro’s been taken over by my son. I’ve got accounts on all my family’s computers, but when they’re all in use I’m reduced to using my work laptop.

My company has a “don’t use company resources for personal projects” policy. Since 2014 I’ve complied with this mostly by being too busy/lazy/distracted to do any personal projects. :-) But now that I’m helping my kids with their programming projects, it’s time to once again consider a personal computer.

Why not an iPad Pro?

I bought the original 12.9” iPad Pro and tried using it as a personal computer. It didn’t work out, because I like to program apps, and the iPad Pro doesn’t let you do much programming. And even if it did, the iPad Pro keyboard is not very good for typing.

The 2018 model iPad Pros have great hardware, including an improved keyboard, but they still don’t allow programming apps.

What’s my budget?

To put things in perspective, my first PC cost over $3,500 in current dollars, my first Mac was $7,000 in current dollars and my most expensive personal computer ever was a Macintosh IIfx at $20,000 in current dollars. I didn’t actually pay $20,000. I was an Apple employee at the time, and they had a “Loan to Own” program with extremely generous employee discounts. My most recent personal computer cost $1,650 in current dollars.

So, all things being equal, I’d say my budget is in the $500-$2,500 range. Perhaps more if there’s a really big benefit.

What do I want to do with it?

  • iOS programming
  • Unix programming
  • Web surfing
  • Content creation

I don’t need a high end GPU. I’m not planning on using it for PC gaming or local machine learning.

Laptop or Desktop?

Over the past few years I’ve been living the laptop lifestyle at both work and home. I like being able to take my laptop on trips. Recently it’s been useful to take my laptop around the house to my different kids as I help them with their programming projects.

So for me I think the laptop portability outweighs the bigger screen and better price/performance of a desktop.

One use case: iPhone development. This typically requires the ability to charge, and debug a USB-attached device at the same time.

The case for an iMac Retina.

Recently I’ve been using an iMac Pro at work. I really enjoy:

  • Speed of compilation.
  • Beautiful 5G screen.
  • Large number of ports.
  • Clean industrial design.

That makes me think that maybe a iMac 5G might be a reasonable choice.

Hardware specs:

  • 16 GB RAM
  • 512 GB SSD

New or used?

I don’t mind used, but it needs to be new enough to run the current version of Xcode.

Upcoming changes:

  • New macbook and iPad Pro TBA October 30th.
  • iMac 5G spec bump October/Nov?
  • New mac mini “pro” some time this year.
  • New mac pro some time 2019

Some possible configs

Hardware Price $
iMac 5K 32GB/512GB (includes third party RAM upgrade) 2400
Macbook Pro 15 32/512 3000
Macbook Pro 13 16/512 2200
Macbook Air 13 8/512 (not retina) 1400  
Hackintosh AMD 16/500 (reuse old monitor.) 900
Hackintosh laptop 600-900
Nothing, keep using current hardware. This is a good option during the school year. 0


In the end I bought a 2019 Macbook Pro 13”. I sometimes regret the small screen, compared to an iMac, but I like the price and porability.

Girls Who Code iPhone App Development Course Review

One of my daughters recently took the Girls Who Code iPhone App Development course.

This was a two-week summer course, taught 9 am to 4 pm in a high school computer science classroom. The first week the girls were taught the basics of the Swift programming language and iPhone App development. The second week the girls formed into 4-person teams and wrote their own iPhone apps.

The girls learned how to use modern software development tools like Stack Overflow, GitHub, and Trello.

Much of the instruction during the first week was by way of working through examples from a private Girls Who Code website.

What worked well:

  • The girls learned the basics of iOS app development, especially the Interface Builder.
  • The girls learned how to work in small teams, how to design apps, how to meet deadlines, etc.
  • The girls were motivated by the assignment of writing an app to improve society/the world.
  • The girls learned how to present their final project to a group.

What could have been better:

  • From watching to the final presentations, it seems like all the teams had trouble merging their changes. Every team reported that they had “lost” files and changes.
    • I think an hour spent explaining how to deal with git merges and conflicts, and more tutor hand-holding during merging would be helpful.
  • The course instructors were not familiar with advanced iOS programming, and could not help teams that wanted to explore more advanced iOS techniques.

Overall I think this was a well run course, with good value for money. It would be appropriate for a high school girl who was already comfortable programming in Python or Java, and was looking to learn the basics of iOS programming.

On-the-cheap Machine Learning, revisited

A short update on my On the Cheap Machine Learning blog post. After almost a year of use, I’m still pretty happy with the setup. The hardware has worked well. I haven’t done as much independent ML research as I had hoped, but I have contributed many hours of night-time GPU cycles to the Leela Zero open-source Go-game-AI project. I don’t think I would change anything about the build, and there’s nothing about it I want to upgrade yet.

However, in the past year a new option has appeared for on-the-cheap machine learning: Google’s Colaboratory project. Colaboratory is a free web-based IDE for writing machine learning applications. What’s especially cool about it is that comes with access to a cloud-based GPU. The GPU they provide is the NVIDIA K80, which is not the fastest GPU, but it’s still plenty fast for experimenting with machine learning. [Disclosure: I work for Google, but not in any groups related to Google Colaboratory.]

Colaboratory puts machine learning within the reach of anyone with a modern web browser, even if that browser is on a device (like a laptop, tablet, or even phone) that doesn’t have a high-end GPU.

I find myself using Colaboratory instead of my own desktop computer simply because my son’s often using my desktop computer for schoolwork, YouTube and playing games.

What I learned in 2017

Shipping an Audio Pipeline

In 2017 I shipped a new audio rendering pipeline for the iOS version of Google Play Music. I use it to render a particular flavor of fragmented MP4 that we use in the Google Play Music streaming music service. It was quite a learning experience to write and ship real-time audio code on iOS.

If you are looking to write an audio pipeline for iOS, I highly recommend basing it on The Amazing Audio Engine 2. Core Audio is a powerful library with an peculiar API. TAAE2 provides a much nicer API on top of Core Audio, without adding much overhead.

I had designed and implemented much of my new audio pipeline in 2016, but 2017 was the year that I deployed the pipeline to production.

I learned that shipping an audio rendering pipeline comes with a long tail of bugs, most of which have the same symptom: “I was listening to a song when it stopped”. I was able to find and fix most of my bugs by using a combination of:

  • Great base libraries. (TAAE2 and Core Audio)
  • A clean, well-thought-out design.
  • Unit tests.
  • Assertions.
  • Playback error logging that is aggregated on the server side.
  • A/B testing. (Between different versions of my audio renderer code.)
  • Excellent bug reports from alpha users.
    • My boss and my boss’s boss’s boss were the two most prolific bug reporters.
    • Several other alpha users went out of their way to help me diagnose bugs that affected them.

The error logging and A/B testing together gave me the confidence to roll out the feature, by showing how well it performed compared to the previous renderer stack.

Learning a new code base

In 2017 I joined the YouTube Music team to work on the iOS version of YouTube Music, which meant that I had to get up to speed on the YouTube Music code base. It’s a large complicated app. I found it difficult to get traction.

What finally worked for me was giving up my quest for general understanding. I just rolled up my sleeves and got to work fixing small bugs and adding small features. This allowed me to concentrate on small portions of the program at a time, and also provided a welcome sense of progress. My understanding of the overall architecture has grown over time.

Learning Swift and UIKit

In 2017 I audited both the iOS 10 and iOS 11 versions of the Stanford iOS programming class. In past years I’ve just watched the lectures. This year I actually did the programming assignments. These classes gave me a thorough understanding of Swift and UIKit. I felt they were well worth my time.

The reason I audited both the iOS 10 and iOS 11 versions of the course is that changes to the Swift language meant that the final programming assignment of the iOS 10 version of the class can’t be completed using Xcode 9. I was only able to finish the first half of the iOS 10 version of the course. When the iOS 11 version came out in December, I was able to resume my studies. I’ve done the first 3 problem sets, and hope to complete more before the end of my Christmas / New Years’ Day holiday.

Learning Machine Learning

I am fascinated by the recent advances in machine learning, especially the DeepMind AlphaGo and Alpha Zero programs.

In 2016 I built a modest home PC capable of doing machine learning, but it sat idle for most of 2017. I haven’t been able to do much with machine learning other than read papers and run toy applications. I am contributing computer cycles to the Leela Zero crowd-sourced Go player inspired by AlphaGo.

As a long-time client-side developer, it’s frustrating that there’s no “UI” to machine learning, and the feedback loop is so long. I’m used to waiting a few minutes at most to see the results of a code change. With machine learning it can take hours or days.

It is also frustrating that there are so many different toolkits and approaches to machine learning. Even if I concentrate on libraries that are built on top of Google’s TensorFlow toolkit, there are so many different APIs and libraries to consider.

Learning to let go of personal computing

In 2017 I continued to adapt to the decline of the personal computer. I am gradually retiring my local, personal computer based infrastructure, and adopting a cloud-based mobile phone infrastructure.

I’m surprised how smoothly the transition has gone. I still have laptops and PCs around my house, but the center-of-gravity for computer use in my family is continuing to shift to phones.

I’m happy that I’m spending less time on computer maintenance.

Looking forward to 2018

My engineering learning goals for 2018 are:

  • Finish the Stanford iOS 11 programming course.
  • Write a small machine learning app.
  • Help my kids improve their programming skills.

Hat tip to Patrick McKenzie for the writing prompt.

The Modern Family's Guide to Technology to take on a European Vacation

This summer I took my Seattle-based family of five for a three-week trip to Europe. We had been promising the trip to our kids since they were little, and this year we were finally able to go. We had a wonderful time!

Using our phones at the Eiffel Tower

Here are my tech-related traveling tips.

Disclaimer: I am not being paid to write this, and there are no affiliate links. I’m writing this to help me remember my trip, and in the hope that it will be helpful to other families (and maybe even couples and individuals) planning similar trips.

Hardware Tips

Take your mobile phones

Take one modern mobile phone per person. Android, iPhone, either is fine, but you’ll want something with a SIM slot and nice camera.

Leave your laptops at home

I didn’t take any laptops with me, and I was able to do everything I needed to do using just my mobile phone. It was a relief to not have to lug around a laptop.

A few times I had to request the desktop version of a web site, but for the most part, the mobile phone worked fine for both apps and web browsing.

Obviously I didn’t do any long-form writing on my phone.

I suppose an iPad, Kindle, or Android tablet would be a possible alternative. It might be a compromise between a phone and a laptop. I didn’t take any tablets on my trip.

Leave your cameras at home

We didn’t take any non-phone cameras with us. Our phone cameras were good enough for most pictures. (Note: if we were going on a wildlife safari to Africa, we’d still take “real” cameras, so we could use telephoto lenses. But for the kinds of pictures we wanted to take in Europe, phone-based cameras worked fine.)

Tip: Most museums, and even most churches allowed people to use their phones to take pictures of the art. This is a welcome change from the “No cameras allowed” policy of the past.

The well-protected Mona Lisa

International USB Chargers

Take international-style USB chargers, that have built-in adapters for foreign wall power sockets. Look for chargers that have at least 2 USB ports, and ones that are rated for 2.1 amps, because that sort of charger will charge your phone faster than a lower-power charger. It’s also nice to get a “pass through” charger, that lets you plug another electrical device into the charger. This is handy for hotel rooms with no extra outlets.

I didn’t use this particular model of charger, but it’s the kind of charger I’m talking about.

Tip: Many USB chargers have ludicrously bright power lights. Before you leave home, cover the power lights with black electrical tape. Otherwise they’ll keep you awake at night in the hotel room.

When traveling in the US I take a larger 6-port charger, so that I can charge the whole family’s devices from one hotel power outlet. (And in my car I use a 4-port cigarette lighter charger.) But in Europe, because we were often on trains with per-seat power outlets, it was more convenient to use multiple 2-port USB chargers.

Take extra chargers and USB cables and ear buds

Take extra USB chargers and charging cables and ear buds. They will get lost and break. It’s convenient to have spares. Don’t bring a too many, though. If you run out, USB chargers and cables and ear buds are available for low cost in vending machines and stores across Europe.

Take battery packs

Take a cheap USB Battery Pack with you. This will ensure you always have at least one working phone, no matter how long you stay out, or how much you use maps / web / photos. In fact, consider taking one pack for every two family members.

Phone cases

Put inexpensive rugged phone cases on your phones, to reduce damage from accidental drops. My family is partial to Otterbox and Incipio cases, but shop around to find something you like.

Selfie sticks

You should swallow your pride and take a selfie stick. It makes it so much easier to take good group photos. Be aware of your surroundings, and don’t annoy your fellow tourists.

I confess that I was too proud to take a selfie stick, and as a result I have very few photos that include everyone in my family. I regret that!

Proof you can take a photo of your whole family without using a selfie stick. But posing options are limited:

Holding hands

Use a mesh bag to organize your electronics

As any backpacker knows, small mesh bags are invaluable for keeping track of small items. Buy a mesh bag from a camping store (or a laundry store) and use it to store all your chargers and cables. For my family, something that worked well was for me to carry the whole family’s chargers and cables. I’d hand them out at the beginning of a train or plane trip, and collect them at the end of the trip.

Phone service

You don’t have to have phone service for your trip. You can get pretty far just using WiFi.

However, if possible, I recommend that you get mobile phone service for at least one of your family’s phones. It is tremendously useful and convenient to have for maps, search, and translation.

Free International Roaming

If you have T-Mobile, get their international roaming plan added to your account before you go. It gives unlimited data and texts in many countries. Bonus: The plan only promises 2G speeds, but we found in several places we were getting much higher speeds. My guess is that some countries have turned off 2G network access, and in those countries you’re getting the higher 3G or 4G speed for free. Presumably this extra speed won’t last forever, but it’s a nice benefit for now.

Expensive International Roaming

My impression is that other US carriers have fairly expensive international roaming plans. But since I’m not a customer, I don’t know the details. Check with your carrier – maybe they have a plan that fits your needs and budget.

Buying a local SIM while in Europe

If you don’t have T-Mobile, most European countries have relatively inexpensive short-term SIMs available for purchase at kiosks in airports. You’ll need to have an unlocked phones to do this.

Potential problems with older Verizon and Sprint phones

If you have an old, pre-4G, Verizon or Sprint phone, that doesn’t have a SIM slot, you will have trouble using European phone networks.

Make sure your phone is carrier unlocked

If you bought your phone from a mobile carrier, it’s probably locked to their network. That makes it difficult to use with another network’s SIMs. Before your trip, contact your carrier and ask them to unlock your phone. They will usually be willing to unlock your phone, but it depends upon the carrier and the terms of your contract. You may have to pay an unlocking fee.

If all else fails, consider buying a travel phone

If you can’t unlock your phone, or if your phone doesn’t have a SIM slot, consider buying a phone just for the trip. As of the fall of 2017 you could get a used unlocked iPhone 5s 16GB for $125. That model phone would make a good travel phone. There are similar deals available on older high-end Android phones.

Receiving text messages while on vacation

If you are using a country-specific SIM while you’re traveling, you may run into a problem. Any text message sent to your normal phone number won’t get to your phone while you are using a different SIM in the phone. This could be a problem for you, because many online services want to send you a text message to verify your identity. You won’t receive the text message while you’re using a different SIM.

The simplest way to deal with this problem is to cross your fingers, and hope that you don’t need to receive texts while you’re on vacation.

The second-simplest way is to sign up for T-Mobile international roaming, at least if you’re already a T-Mobile customer.

If you’re a customer of another phone company, you might consider signing up one of your phones for an international roaming plan, that lets you receive and send texts to/from your US phone number while traveling. Even if it’s expensive, it may save you a lot of trouble if you need to receive a text message while you’re on vacation.

If you’re an advanced techie, you could consider signing up for a VoIP service (like Google Voice), which allows you to send and receive text messages over the web. It can also be set up to forward your voice calls from your main number to your travel SIM number. But using a VoIP service is complicated. It’s probably more trouble than it is worth for most people.

WiFi, power, and mobile phone coverage

Here’s what I found in my trip, which covered Spain, Paris, and Frankfurt.


Most tourist hotels and apartments have some form of WiFi. Usually it’s free with your room, although some high-end or business oriented hotels will charge you. Hotel WiFi can be slow and flakey.

Many tourist restaurants have free WiFi. Ask your server for the password.

Many museums have free WiFi. A few museums have QR codes on exhibits that you can scan to learn more about the exhibit item.

Some towns have some form of public WiFi, but I was never able to get it to work.

Most airports have free WiFi.

Some high-speed trains have WiFi, either free or paid.

Unfortunately there is currently no transatlantic plane flight WiFi service. I think it’s a technology limitation.

USB / wall power

USB and wall power plugs are available at each seat on most planes and high- speed trains. The wall power plugs are European-standard plugs and voltage.

Just as in the US, many airports have at least a few USB ports and electrical outlets scattered around the waiting area.

In Madrid I even found USB charge ports installed on one of of the transit buses!

Mobile phone coverage

Mobile phone service is very good in major cities. Mobile phone service can be spotty in the countryside.

Lunch with phones on a Spanish high speed train:

Lunch with phones on a Spanish high speed train

Keeping your phones from being stolen

Unfortunately, pickpockets and thieves are common in tourist areas of major European cities. Your phone is an easy target. Thieves like to steal phones because:

  • They’re easy to steal.
  • They’re valuable.
  • Older phones can usually be unlocked, erased and sold.
  • Newer phones, that can’t be unlocked, can still be stripped for parts (battery and screen) that can be sold.
  • SIMs can be taken out of both old and new phones
    • An unlocked SIM can be used to charge money to your phone bill.
    • An unlocked SIM can be used to receive texts sent to the SIM’s phone number, useful for identity theft.

You can take some steps to minimize the potential problems of theft:

Take your older phones

If your family has several generations of phones laying around, consider taking the older phones. That way you won’t feel as bad if they’re broken, lost, or stolen. Of course you have to balance this against the benefits of taking your newest phones, which will have the best cameras.

Wear anti-theft clothing

Consider buying some pickpocket-proof pants. If you cary a purse or small bag, store your phone in a hard-to-get-into zippered internal pocket. Figure out a way of carrying your phone so that it’s in front of you, where you can keep an eye on it. Some backpacks have phone pockets on the shoulder straps.

Don’t ever leave your phone on a table in a public place.

Turn on “Find my Phone”

Both Android and iPhone have an optional feature you can turn on to make it easier to find a lost phone. It’s called Find my Device on Android, and Find my iPhone on iOS.

Tip: Thieves know to power off stolen phones to prevent them from being tracked. But the feature is still handy for finding phones that are lost or misplaced rather than actually stolen.

Put a passcode on your phone lock screen

You should have at least a 4 digit passcode on your phone lock screen. In addition to keeping thieves from being able to erase your phone in order to resell it, this will make it harder for thieves to break into your phone to steal your identity.

SIM Lock your phone SIM

Add a PIN to your SIM card. Having a PIN on your SIM is annoying, because you’ll have to type the PIN to unlock your SIM every time you reboot your phone. But having a SIM lock can save you a lot of trouble and money if thieves steal your phone. Without a SIM lock, the thief can take the SIM card out of your phone, put it into another phone, and then charge hundreds of dollars to your phone account by calling for-pay telephone numbers.

Without a SIM lock, thieves can also put your phone’s SIM into another phone to receive texts sent to your phone number. An ambitious thief could use your phone’s SIM to hijack your online accounts.

Know how to report a lost/stolen SIM to your phone carrier

If your phone is lost or stolen, you should report it to your phone carrier right away. If you’ve put a lock screen passcode on your phone and added a SIM lock, you probably will be OK. But there is always a chance that the thief has figured out a way to bypass those lock codes.

Tip: Print out your phone account information (carrier customer service number, account number, your phone number, and the SIM serial number) and carry it with you on your trip. Keep that paper separate from your phone. (Do the same for your passports!)

Keeping your accounts from being stolen

Be careful when you use public WiFi. Just as in the US, using public WiFi in Europe means it’s possible for bad guys to listen in on the data being sent and received by your phone. Bad guys can even set up fake servers, that pretend to be Facebook, or Gmail, or your bank, and try to trick you into revealing your login name and password.

Just like in the US, there are things you can do to make it less dangerous to use public WiFi in Europe:

  • Avoid using “high value” web sites, like your bank, from public WiFi.
  • Avoid visiting “http” web sites from public WiFi. “https” web sites are more secure.
  • Use an up-to-date version of your phone’s operating system.
  • Use up-to-date versions of your apps.

Tip: Before you leave the US, consider turning on “two factor authentication” for important accounts. Two Factor Authentication will make it harder for identity thieves to impersonate you. However, there is a tradeoff. Most “two factor authentication” systems use text messages. This means you’ll have to be able to receive the text messages while you’re traveling, which means you’ll have to set up international roaming for at least one of your phones.

Essential apps

Tip: I work for Google in my day job, so the following list is a little Google-centric. 😇

Google Docs

Use Google Docs App Store Play Store to share a trip itinerary with your family. (You can also share an edited version with parents and neighbors.) An itinerary is a day-by-day list of what you are doing. Put in dates, cities, flight and train times, hotel contact info, and “must see/do” lists. Using a shared document makes it easier to keep the information up to date.

Tip: Turn on “offline mode”, which stores a copy of your documents locally on the phone, so that you can read and edit them even when you don’t have internet access.

Google Maps

Google Maps App Store Play Store is hugely useful when traveling in Europe, not just for maps and navigation and transit directions, but also for local restaurant and attraction reviews. I felt like a local being able to read the auto-translated reviews of all the bakeries and grocery stores near my hotel.

Tip: Download the area you’re planning on visiting as an offline map. That way you can get around even if you don’t have WiFi or phone service.

Tip: Double-check opening hours, since Google Maps doesn’t always list the correct opening hours, or account for local holidays, or restaurants being closed due to the owner’s vacations.

Tip: Google Maps lets you mark map locations using various icons. For example I found it helpful to mark my hotel on the map, as well as any sites I was interested in seeing in that city. That made it easier to plan my day, and to plan what to do next. I could quickly look at the map and see if there was anything within walking distance.

Vietnamese food was a welcome treat. Tastes just like back home! Restaurant found with Google Maps.

Vietnamese Food

Google Photos

Google Photos App Store Play Store provides free unlimited photo and video storage. It also provides an excellent photo search feature.

The way my family used Google Photos during our trip was that we would take pictures and videos during the day. Then, each evening, when we returned to our hotel, we would bring the Google Photos app to the foreground, and keep it there while it uploaded the day’s pictures and videos.

Some hotels had very slow WiFi, so sometimes we had to wait until we got to a better hotel to do this.

Once the upload had finished, we used the “Free up space” menu item to delete all the locally stored photos, which freed up phone storage for the next day’s photos and videos.

Tip: Whenever you pass a restaurant or store or attraction you’re interested in visiting, take a picture of it. That can be helpful when you’re trying to remember the name of the restaurant the next day.

Google Translate

Google Translate App Store Play Store is able to translate many signs and menus. And while many people in Europe speak English, it is sometimes useful to be able to translate an English phrase into the local language.

Tip: Use Google Translate to translate text on menus and sign. Tap on the camera icon in the app.

Tip: Download a language pack for each country your visit. This enables Google Translate to work even when you don’t have WiFi or phone service.

Google Hangouts

Google Hangouts App Store Play Storeis a free group messaging app.

My family used Google Hangouts group messaging to stay in touch, not only with each other, but also with grandparents back home. We got into the habit of sending a few highlight pictures and a short description of our day’s events to the grandparents each day. It was easy to do, and afterwards we saved the conversation as a nice record of our trip.

Tip: There are many other group messaging apps, use whatever one your family is comfortable with.

Tip: Include grandparents in the group chat, it makes it more fun to have an audience to share your stories with.

Tip: If you’re staying at apartments rather than hotels, you may need to download a country-specific chat application to stay in touch with the apartment landlord. For example, WhatsApp is popular in some European countries.

We watched the Bastille Day fireworks on cable TV in our rental apartment in Paris, while in a group Hangout chat with my mom back in America, (She was watching on a live-stream.) Eiffle Tower Bastille Day Fireworks

Google Keep

Google Keep App Store Play Store is a handy To Do list app. I used it to keep track of snippets of information about places I wanted to visit, as well as tasks to do when returning to the US.

Google Trusted Contacts

Google Trusted Contacts App Store [PlayStore] is a cross-platform app that lets you see where your family’s phones are in real time. Handy for meeting up in a large museum, at least as long as GPS reception is good.

Tip: If your family is 100% iPhone, Apple has a similar, iPhone-only “Find my friends” app.


I had a TripIt Pro account through my workplace. It was helpful because it kept me up-to-date on the status of my airplane trips. Things like telling me when the plane had arrived, which gate it was at, and when the flight was delayed.


TripAdvisor is a good source of information on attractions and restaurants. Its UI is a little slow, and it tries hard to up- sell travel packages. But if you can get past all the advertising, it’s a good resource for finding out what to see and do in a new city.

Inessential, but fun, apps

Consider using a diary app to keep track of you trip.

The text adventure game 80 Days App Store Play Store is fun to play while traveling.

Similarly, Old Man’s Journey App Store Play Store and Burly Men at Sea App Store Play Store are fun quick travel-themed adventure games.

You can use your standard social and media apps while traveling. Instagram, YouTube, Google Books, Google Play Music, and so on. For media apps be sure to download media ahead of time, to be able to use the app while you don’t have network connectivity.

Buying attraction tickets online

Most of the large museums and attractions in Europe have online ticket sales. The museum web site usually has an English-language page. You pay by credit card, and you receive the ticket as an email containing a PDF file. You are instructed to print out the PDF and bring it with you to the museum.

You don’t need to print out the ticket, though. It is also possible to show the PDF on your phone screen. The ticket PDF usually has a bar code (or QR code), and the ticket-taker’s bar code scanner will usually work with the phone screen just as well as on paper.

Tip: Be sure to zoom in far enough that the individual stripes of the bar code are visible.

Tip: Sometimes it’s helpful to use your phone’s web browser’s “Request Desktop Site” mode, to request the desktop version of the web site. Sometimes the desktop web site has more information and/or features than the mobile version.

Tip: Take cropped screen shots of your family’s tickets’ QR codes, and arrange them all together in your phone’s photo gallery. This makes it easier at the ticket gate, since you can quickly swipe from ticket to ticket, to quickly present all your family’s tickets to the ticket taker.

If you don’t know how to take a screen shot on your phone, ask your kids. 😁

Tip: Contact your credit card company before you travel, and let them know that you will be traveling to Europe. Doing this can help you avoid having your credit card declined due to unusual account activity.


Mobile phones are essential for modern traveling. The last time I went to Europe, over 20 years ago, I had to use paper guide books and pay phones and post cards and a film camera. Revisiting Europe today, with mobile phones, it was so much easier to get around, and I think I saw more things. I certainly took more pictures!

If you read this far, I assume you’re planning your own trip to Europe. I hope that this article gave you some good information to help you have a good trip. I hope you and your traveling companions have a great time!

A family we met in Madrid:

A family we met in Madrid