Starting with the iCade and followed by the more compact iControlPad now the giant Atari released a bluetooth gadget that connects to your iPad or iPhone as a keyboard, offering great physical controls for great games.
With the update version 10.113, the developers of GLBasic offer a built-in support for these devices. Programming is very easy, because from the programmers point of view the iCade was implemented as if there was a 2nd joystick attached to a PC.
GLBasic is a free programming language that supports a huge variety of target platforms. The "premium" SDK purchase offers support for many mobile devices, 3D graphics and networking action."