Compasso turns your compass into a synthesizer. You select one of 3 things the compass can affect: (1) Resonance/Cutoff, (2) LFO Rate, (3) Oscillator detuning.
Tipping it also affects the keyboard octave (Left to Right)… and LFO depth (Front to Back). You also have a few settings to change your starting point, as well as some rhythm accompaniment on the back (flick up to find it).
This miniSynth is really well done, “fun” to use. A Super miniSynth for iPhone.