For the Apple ipad2:
The technology was originally invented by NASA to be used by autonomous vehicles on space missions. Our implementation uses the camera of the mobile device to build 3D maps of the surroundings in real-time and determine the device’s location and orientation within these maps.
Sounds and looks really interesting! I’d like to see it used for a more graphic intense realistic looking FPS game.
You can buy it at the Apple App Store if you have an ipad2 – HERE