TNCheckBox – A checkbox class for Objective-C

I just pushed some code to GitHub to create customisable checkboxes to use in your IOS projects.

As it happens with designers, you can’t always use the built-in UISwitch class.  So I took the time to create a few classes which are pretty customisable to have checkboxes without all the hassle.

I’ve created 3 classes for the most common checkboxes, but it’s really easy to extend the class with your own requirements.  I’ve posted all the details on GitHub.  When you toggle the checkbox there is an animation. You can always override the animation method if you would like to do some other animations.

TNCheckbox for IOS


You can find the code on GitHub. If you have any requests, put them in the issues panel.  I’ve tested as many scenarios as I could, but if you find any bugs, please post them as well!

iCapital 2.0 iPhone app

I’ve just released version 2.0 of the iCapital app, which is completely redesigned for iOS7.

iCapital was my guinea pig project to learn about Objective-C a few years ago, and since then I didn’t have the time to update it for iPhone 4 and 5.

With the arrival of iOS7 I’ve took the time to polish this baby up according to Apple’s new guidelines and look’n'feel! Hope you’ll enjoy learning about the world!

Download it now for only half a glass of beer (0.89 cents) in the App Store and if you have any requests, just post them in the comments!

List of countries and capitals of the world (json, xml, csv)

For the upcoming release of iCapital 2.0 I needed a list of all the countries and capitals of the world in json format. I searched the web, but couldn’t find a proper solution until I found these lists on GitHub.

Sadly they only contained the countries of the world, so on a boring Sunday night, I’ve extended the list with all the capitals for those countries!

Next to the countries and the capitals, the lists also contain:

  • top-level domain (tld)
  • code ISO 3166-1 alpha-2 (cca2)
  • code ISO 3166-1 numeric (ccn3)
  • code ISO 3166-1 alpha-3 (cca3)
  • currency code(s)
  • calling code(s)
  • alternative spellings
  • relevance
  • region
  • subregion

Go check them out right here!

This is how I learn my ABC version 2.0

Hi all,

We’ve been working around the clock last month to push out a new version of ‘This is how I learn my ABC’.

By popular demand the app has now become an universal app, which means it will run on your iPad, but also on your iPhone now … for free :-)!

If you go to the App Store on your iPhone and you have purchased the iPad version you will see a ‘Buy’ button, but don’t worry, just purchase the app and Apple will show you a message which says ‘You have already purchased this application, this upgrade is for free’.

The app has been totally rewritten for iOS7 using Apple’s new gaming framework SpriteKit to get optimal performance and we’ve added new goodies as more sounds and animations. Game Center integration is also available so try to unlock all the achievements!

Go check it out on the App Store!

In the meanwhile we are working very hard on another big update which will fulfil the second biggest demand … the Dutch version! This will also come as a free update :-)

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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Grading in the future?

As partial exams just passed at my work (, the job of carefully entering grades takes a lot of time. A common workflow is

  1. Correct grades on paper
  2. Input grades in a spreadsheet with partial grades
  3. Double-check grades on paper with grades in spreadsheet
  4. Merge partial grades in a new spreadsheet with global grades
  5. Input grades in school system

As I was working I was thinking about how nice it would be if I could just speak to my computer and the grades would be filled in automatically.

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