iGPUTrace creates fully interactive photorealistic images of shiny spheres in photographed environments. The compass and accelerometer controls the camera movement in 3D space. For more complex shapes check out the "Quaternion Julia Raytracer" App.
IPhone GPU Raytracer is the first real-time raytracer for the IPhone 3GS and new IPod Touch. It utilizes the PowerVR SGX GPU for raytracing using OpenGL ES 2.0 shaders.
The Settings tab allows to enable an environment that is mirrored on the scene objects. If you have red-cyan glasses available, you can see the scene with real depth by enabling stereo mode.
A one finger drag rotates the camera around the object, a two finger pinch is used for zooming and a three finger drag translates the camera.