The best selling Xbox Live Indie Game, The Impossible Game, is now out on the App Store - and you can play the free browser-based lite version!
You control an orange cube, and the only control is to jump by tapping the screen. The aim is to get as far as possible by jumping over spikes and jumping on blocks. Any mistakes and you go back to the beginning, and with an awesome soundtrack synced to the level it becomes incredibly addictive!
Check out http://www.flukedude.com/ for more info, and remember you can buy The Impossible Game on the App Store!