Making kids happy one shape at a time

As a software developer, I spend my life writing line upon line of code with the idea that someone, somewhere will eventually use whatever software I’m building. Assuming that yes, someone does in fact use the software I build, I can only hope that these imaginary people actually enjoy using it!

Recently, I received this video from a close family friend of mine.

Watching this little boy play Shape Matcher, listening to his laughter and seeing his smile – I think I can say that in this particular case, at least someone has enjoyed using my software :)

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Mobile app’s first steps – so far so good!

My third iOS app, Shape Matcher, launched almost exactly a week ago. I’ve been watching my Localytics analytics with much anticipation hoping to see the number of downloads rise. And I am proud to say that for once, my app is actually being downloaded AND used more and more!!

Since (upward-trending) graphs make me very happy, I thought I might share some graphs with anyone who might be interested.

New and returning users

Both the number of new and return users is rising. I had a big day on Sunday, possibly related to the fact that I wrote a blog post about the tools I used to build Shape Matcher but more possibly also because people spend more time with their children on Sundays, although that’s just a wild guess really.

Shape Matcher - so far so good!


The number of sessions seems to be rising fairly steadily.

Shape Matcher - so far so good!


It looks like the iPad 2 is the most common device amongst my target audience (mostly people with children).

Shape Matcher - so far so good!


I’ve had far more users and sessions from the USA than anywhere else. It really make me feel warm and fuzzy to know that people in 62 different countries have played my little game though :)

Shape Matcher - so far so good!
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Tools I used to create a simple iOS game

My latest iOS app, Shape Matcher, was recently released into the wild. It’s an iOS (available on iPad and iPhone) shape matching game for young kids’ – about all the gaming logic I can handle as a night-time Obj-c novice. Anyway, I figured it might be useful to others if I documented what software, frameworks and tutorials I used to develop it.

Shape Matcher


  1. Inkscape

    Inkscape is an awesome open source vector graphics editor. One of the things about writing a game is that you’ll probably need to draw some cute backgrounds or characters. Unless you’re a designer who already owns a copy of and knows how to use something like Illustrator or Photoshop, you’re going to want this software.

    Drawing itself is a skill I don’t really have, and that really sucks. These days, apps have to look as good as they work. I might be good at writing software but I’m really not very good at drawing stuff – or at least that is what I was convinced of until Jas and I finally sat down and tried to learn how to draw digitally. We followed a fantastic tutorial called 2D Game Art For Programmers – Part 1 and by the end of it, we weren’t too bad at drawing some nice scenes and basic characters. All it took was for us to sit down and actually put our minds to it and it turns out that we’re not that bad at drawing after all!

  2. Zwoptex

    If you plan on including lots of images in your iOS game, you might find it easier to use sprite sheets instead of lots of individual images. This is especially true if you plan on supporting different devices with different resolutions (because you need to supply resized images for each differently sized device). Zwoptex is a tool that allows you to create sprite sheets from your original images. You can then use Cocos2D’s built-in support to load the sprite sheets in your game. You can download Zwoptex for free, and if you don’t purchase it, it will take a couple of seconds longer to export the sprite sheets but it will still work properly otherwise. Much recommended!!

  3. Sublime Text

    There seems to almost be a little bit of a cult following around Sublime Text. I’ve heard lots of well-known developers say that they use it as their primary code editor. It does seem to be nice and fluent. There are a few things about the UI that make it stand out. I use it when needing to copy plist values from the temporary files that Zwoptex outputs to my app ones. It certainly does the trick.

  4. GarageBand

    Most games have some sort of sound effects or soundtrack. Luckily cocos2d, the gaming framework I use, allows you to include sounds in your game really easily. But you still need to make your sounds or edit open source ones you find online. GarageBand provides a nice interface to do just this. You can then export them as .mp3 files and include them in your Xcode project. Simple!


  1. cocos2d for iPhone

    cocos2d for iPhone is a framework for building 2D games. It adds support for important gaming functionality like transitions between scenes, sprites and sprite sheets, effects and actions, menus and sound… just to name a few. Shape Matcher is the second iOS game using cocos2d that I’ve worked on. Earlier this year, Jas and I wrote and released Easter Egg Hunt, also using cocos2d. So far we are both very happy with the framework as it provides a lot of functionality that I wouldn’t want to try and write from scratch. The only criticism I have right now is that the latest stable version, cocos2d-iphone-2.0, does not have support for the new iPhone 5 Retina Display screen resolution. Version cocos2d-iphone-2.1 beta3 does, but it’s still in beta. Either way, you can get around it in code if you need to.

  2. Localytics

    Localytics offers integrated app analytics for your apps. They have an iOS library that you download and link to in your app. You can then track certain events in your app, such as when a user clicks a particular button or when they’ve spent a particular amount of time on any one scene. This information can be truly invaluable and the Localytics library makes it super easy to use. Their website, where you can view graphs about your app’s usage, is easy to navigate and nicely responsive. They aren’t free but they offer a free trial that doesn’t end, as far as I know. You have to pay to access some of the more interesting reports.

  3. In-App Purchases

    Although it can take months to write even a semi-decent iOS game, most people aren’t prepared to part with even $0.99 USD for it. I’m not quite sure I’m prepared to spend hours upon hours writing games that don’t make me a cent in return, but I would like people to actually play my games! In terms of games, this is where In-App Purchases come in very handy. You can put your game on the App Store for free, but sell extra scenes or options from within the game itself.

    Luckily, Apple has made it pretty easy to integrate In-App Purchases in your application and theres a ton of help on the internet on how to use it. I used one of Ray Wenderlich’s awesome tutorials, Introduction to In-App Purchases, to learn how to include some in-app purchases in my game.

Tips and tricks


It’s a good idea to create both ‘test’ and ‘live’ versions of your app on Localytics so you can test your integration with them and not pollute your ‘live’ analytics. Just before you archive and submit your app to be reviewed, change the Localytics app ID in your code to the ‘live’ one. Don’t forget to do this!!

In-App Purchases

Although I totally missed it in the Apple documentation, apparently if you have any In-App Purchases in your app, you must provide a ‘Restore Purchases’ button in case the user installs your app on a new phone and has already made purchases. This button seems somewhat overkill since clicking on the buy button again will allow the user access to the purchase without charging them again but I guess it’s nicer for the user to click on a ‘restore’ button than a ‘purchase’ button. Apple app review staff will reject your app if you don’t provide this button. Ask me how I know this…


When creating the individual images that you’ll use in your game, export them in the largest size you’ll need them from Inkscape. Import them into Zwoptex to create a sprite sheet and save this workspace. You can then set up the publish settings to export one sprite sheet for each device resolution you want to support (except for the iPhone 5 that actually has a different ratio). When you press the ‘publish’ button, Zwoptex will create a spreadsheet per setting. This saves a lot of time when you’re writing a universal iOS game and keep making subtle changes to your drawings.

Zwoptex Example

Below is a handy table of iOS device sizes that you’ll want to use in your publish settings for each iOS device:

iPad Retina 100%
iPad 50%
iPhone Retina 46.875%
iPhone 23.4375%

So what are you waiting for? Go download these tools and get started on your first iOS game! If you have any questions, please feel free to ask :)

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500km in one year

One year ago today I started keeping track of my running. I had just joined a new gym and Jason and I had made a pact to really give the gym a go this time. Little did I know what this would lead to…

During this last year I participated in a 5km run with my dad and brother in Santiago, Chile and a 16km run with my workmates and friends here in Amsterdam. I bought myself fancy new Nike Lunarglide running shoes and a bluetooth heart rate monitor. I managed to get to the gym 82 times and started running outdoors.

But best of all, I ran a total of 500km in one year.

Running Log - Distance (kms)

I for one would never have thought I could run that far in a lifetime, let alone one year. Yet, here I am, 500km later and only 2 weeks away from running my first half marathon. I must admit, I’m pretty nervous about running 21km. I’ve never actually run any further than about 18km in one go so 21km is going to be a stretch. But then again a year ago I didn’t even think I’d be able to complete the 5km run with my dad and brother without collapsing.

So there we go. A pat on the back for me. I’m proud of my efforts and am looking forward to another year of good, hard exercise. Who knows, maybe this time next year I’ll be able to blog about having run a whole marathon… :)

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What to see and do in Amsterdam

Since moving to Amsterdam about 10 months ago, we’ve had just about as many visitors. For a multitude of reasons, Amsterdam is incredibly popular with tourists. Every weekend the population of this small city swells ridiculously. In 2010 alone, 5.3 million tourists visited Amsterdam. That’s a lot of people in a very small area!

Anyway, for all our future guests and anyone else visiting Amsterdam, here is my list of attractions. They’re not in any particular order and I know I’m missing a bunch, but it’s a start!


There are a lot of museums in Amsterdam, most of which seem to be art related.

Amsterdam - Rijksmuseum

Rijksmuseum – Image sourced from Wikipedia – Amsterdam Rijksmuseum


There are several old churches dotted around Amsterdam. It may seem a bit strange but Oude Kerk is right in the middle of the red light district!

Amsterdam - Westerkerk

Westerkerk – Image sourced from Flickr – Steve Cadman – Amsterdam Westerkerk


You can spend days just wondering the streets of Amsterdam. The buildings are so beautiful and well maintained. The tree-lined canals and little bridges just can’t get any more picturesque on a sunny afternoon. But then again, there are heaps of other things to do as well, such as…

Amsterdam - Heineken Experience

Heineken Experience – Image sourced from Info Barrel – Heineken Experience


For such a small city, Amsterdam has several particularly well known areas. Some are pretty obvious (like the red light district) whilst others are much more hidden away (like the Begijnhof). Whatever your style, there’s something for everyone.

Amsterdam - Red Light District

Red Light District (De Wallen) – Image sourced from Wikipedia – De Wallen


Like every proper European city, Amsterdam has its fair share of markets. Some only operate on the weekend and most have a particular theme.

Amsterdam - Flower Market

Flower Market (Bloemenmarkt) – Image sourced from Wikipedia – Bloemenmarkt


Shopping in Amsterdam is not like it is in the USA or Australia where you have everything you could possibly need in one large shopping mall. Malls like that don’t really exist in Europe where shopping is more ‘boutiquey’. There are shops dotted around the city and a few streets, like Kalverstraat, are lined with them.

Amsterdam - Shopping Street Kalverstraat

Shopping (Kalverstraat) – Image sourced from Flickr – Kevin Oliver – Kalverstraat Shopping, Amsterdam


Dutch cuisine is not particularly varied but there are definitely some dishes you must try while visiting Amsterdam or Holland in general.

Amsterdam - Fondue

Fondue – Image sourced from Life In Amsterdam

Day Trips

Holland is a tiny country. It really is. Nowhere in Holland is more than an hour or two away from Amsterdam so there are lots of options for day trips. Public transport (both train and bus) is very convenient, comfortable and affordable.

Zaanse Schans

Zaanse Schans – Image sourced from

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