Is there anything an iPhone app cannot be programmed to do?
CubeCheater is an amazing app for iPhone and iPod Touch that, given the current state of your Rubik’s Cube, will tell you how to solve the puzzle in just a few moves.
You can either input the cube’s state using the color palette and tapping in the colors, or you can just take a picture of each face of the cube and CubeCheater will use advanced computer-vision techniques to recognize the cube for you. (The camera feature is obviously not available on iPod Touch)
The app uses the famed Kociemba algorithm to find a solution quickly. It finds optimal or near-optimal cube solutions in only a few seconds. Even a really mixed-up cube will only take about 20 turns to solve, compared to hundreds of turns for a typical human algorithm.
By getting all Beatles Revolution #9 on it, you can also use CubeCheater to put your cube into pretty-looking patterns. Start with a solved cube, input the pattern you want, and solve it. Play the solution backwards to put your cube into that configuration.
The app’s most recent update adds support for different styles of cubes, such as the Blue-opposite-White cubes sold in Japan. You can also specify your own custom cube configuration if you have a non-standard cube.