What can you do with the Cube? Obviously, mentalism. At the simplest, you can divine the number your spectator is thinking of but I think that would be a waste and would draw attention to the die, which is not really what you want.. You can do a lie detector test. You can go further and do more elaborate mentalism routines such as book tests. But we are not all mentalists, and not all audiences are receptive to mentalism. The Cube has been tested in real life working conditions - weddings, restaurants, and walk around, and I include three tried and tested routines that have been proven workers, even with - let's say - boisterous audiences.
As well as being able to tell you which face is uppermost, an additional feature is motion detect mode. By putting the Cube into this mode, a whole new range of effects becomes possible. As soon as the Cube is moved, even slightly, you receive a signal. This enables you to discover which hand a spectator is holding the Cube in (Kurotsuke) - by holding their wrists and slightly moving them up and down - or to discover which of several spectators is holding the Cube (and which ones are holding a non-gimmicked die). Or to detect when the Cube has been moved.