Codify for iPad lets you create games and simulations — or just about any visual idea you have. Turn your thoughts into interactive creations that make use of iPad features like Multi-Touch and the accelerometer.
Can imagine that a Bluetooth keyboard is strongly recommended here π
See also Kodu:
http://teusje.wordpress.com/2011/03/16/kodu-game-creator-new-build-for-pc-released/
and TouchStudio:
http://teusje.wordpress.com/2011/04/12/touchstudio-touchstudioapp/