Getting more serious about VR... the HTC Vive is extremely cool, but quite some investment for starters. Decided to get myself a decent Android phone and a Gear VR, and started porting my astronomy app Cor Leonis to Unity.

Good progress so far! Stars, planets, moon, and sun are all in, reading device location and compass is a breeze in Unity, so I can already have a view of the current night sky in VR :)

Now on to make things pretty and creating a cool experience!


I recently published version 2.0 of my iPad App Lightbox Trace, introducing a filter panel as an optional In-App feature. This really comes in handy, when your sketches don't have enough contrast or you want to desaturate a colored image before tracing. Check it out!

Unfortunately, I ran into a problem with enabling the In-App purchase, so it just didn't work for about a week. If you tried and got an error message about not being able to connect to the App Store, please try again. It really should be working now. If there are still any problems, please send me an e-mail. I appreciate your support!



I'm currently spending a lot of time drawing on my iPad Pro, and needed a way to transfer my digital sketches to drawing paper. Essentially, a lightbox with the ability to display an image. Since I still had my old first-generation iPad lying around, I developed a simple little app to put it to use again: Lightbox trace.

  • Load an image from photos or the clipboard
  • Scale, position, rotate as desired
  • lock the screen - the app now ignores all touch events, so you can put a piece of paper on the display and trace the image
  • display brightness is automatically increased to the maximum
  • you can also just show white, for tracing from one paper to another

I've found it to be quite useful - please try it (it's free!) out and let me know if there is anything you might want to be added.


Now available in the App Store for iPad and iPhone: Flutterby! This app is probably best described as a creative toy - as a user (player?), you guide a butterfly, named Sparky, through a bunch of colored spheres. Pick one to load Sparky with color, and chase down the floating bubbles - they will explode into a range of flowers. Step by step, you create a floral pattern, which you can save to you image roll for further use. Try it - it's fun, and it's free!