Particlescape - Particlescape app lets you create stunning patterns at your fingertips.
TripleA - TripleA is a free (under GPL) turn based strategy game based on Axis & Allies board game.
Heat Pad - Heat Pad – Relaxing Heat Sensitive Surface is a beautiful app that simulates multiple heat-sensitive surfaces reacting to the heat of your fingertips.
ThumbZilla - Awesome thumb stomping and kicking action game.
Warlight - Warzone is a customizable Risk-like strategy game where you compete with your friends to conquer the world.
Fluid dynamics - Fluid dynamics developed and published by Reinder Nijhoff.