I just released a new app (at the time of writing, it's being reviewed by Apple)! Get it on iTunes. It is a gimmick drawing app, based on some fancy OpenGL shaders I created for the desktop (see the video below). It's free and will remain free as long I don't add extra features. I am planning to do some fancier shading effects for the iPad 2 and the new iPad. I hope you'll enjoy :).