National Geographic UIKit Animation transition demo

This afternoon Thomas Degry (one of my students, asked how he could program the neat little effect they use in the National Parks iPad app made for National Geographic. If you want to see the effect yourself, I suggest you download the app to check it out. Just select one of the parcs and then tap on the stats or the weather button. You’ll see a nice transition in which the master view ‘steps’ into the background, while the new content is placed in front of it.

It took me a few minutes of tapping to see how the animation works, so here is how you can mimic the effect. Just play with CALayers and some transformations 🙂

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iCapital v1.5 released

This week a new version of iCapital got released in the App Store. It was my guinea pig app to learn myself Objective-C this summer when I broke my foot. It was an excellent learning app, because it covered a lot of new concepts which I had to tackle:

  1. Core Data
  2. Migrating data on updates
  3. Memory management
  4. Retina support
  5. Game Center

Now, 8 months later, I took a look at how I left my code behind in my repository and I thought it was a good thing to rewrite the whole app as I now have a much better understanding of the language.  Since then I created a new game Boring Meeting OXO, an iPad app (in a private store, but you can take a look how it works here, this was still in a development phase), and a few personal apps.  As I feel myself comfortable with the language now, I hope I can release many new apps soon (one is coming pretty soon :-)!

As with every update, I give away some promo codes you can redeem via the App Store. So for the quick readers, here are 10 promo codes:


I hope you have fun with it!

Debug IOS applications with Charles Web Proxy

When you are doing (naughty) stuff with the Internet, Charles Web Proxy is probably the most valuable thing a developer could have!

Normally I just use Firebug’s Net panel to see what my request/responses are, but since I’ve discovered Charles it took debugging and inspection to a whole new level. Especially now I can hook it up to inspect the traffic sent to and from my iPhone. Continue reading Debug IOS applications with Charles Web Proxy

Forms with UITableview in IOS

When you’re developing IOS apps you often need user input to receive some data.

You have the following options to get the data from a user:

  • Poorly designed form on a rather ugly white background
A rather ugly form
A rather ugly form
  • Use Storyboard to get static UITableviews in which you can easily create a nice form
A form by using static UITableview
A better looking form by using static UITableview

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How to do a lightweight Core Data migration

Why do you need to migrate?

When you release an app and add new features, there will be a time you need to update you persistent store. This is easy to do when you are in a development stage, because you can just delete your app and the persistent store will be re-generated. But when you are live and people have downloaded your app, you need to be careful. They won’t like it if suddenly their saved data has disappeared!

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iOS Face recognition

There is a nice API for face/person recognition on the internet at
Their API provides quite a lot of interesting data, such as

  • Position of the eyes
  • Position of the nose
  • Position of the mouth (right, center, left bounds)
  • Yaw/roll/pitch rotation of the detected head
  • Attributes: gender, wearing glasses, smiling, mood, …

And the best of all … it’s a free service which gives you 5000 calls an hour to their API which is more than enough for a little experiment.

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Boring Meeting OXO – a new way to have fun meetings

After finishing up iCapital, I was thinking about a new app to learn some extra API’s or frameworks.  We were discussing about games during meetings, and that was my eureka moment.  You probably know the feeling when you are in a boring meeting and you want to play OXO with a collegue … passing the paper and thinking ‘oh damn, it’s so obvious we aren’t paying any attention’.

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iCapital – an app to learn the countries a fun way

Due to a broken foot this summer, I finally found the time to investigate the objective-c language.

As a result of this, I’ve just released my first app to the App Store … iCapital!

It’s a little app which let you search for any country in the world and it will tell you what the capital is. You can also do an inverse search (so if you know the capital and you want to know the country). If you want additional data, the app connects to Wikipedia!

Continue reading iCapital – an app to learn the countries a fun way