Theriphone

Theriphone is a fun little app that turns your iPhone into a theremin - pitch, volume, vibrato, waveform mix and whether or not playing uses a chromatic or continuous scale can all be mapped to where you’re touching the screen, or to any of the pitch, yaw, roll and compass heading sensors, or acceleration.

Theriphone uses two oscillators, which can be detuned from each other and/or use the same or different scales and note-ranges. For musical use, pitch can be mapped to vertical or horizontal position on screen. For wilder effects, you can map it to device rotation, or even whether the device is aimed north or south or in between.

Each oscillator has two waveform shapes it morphs between, based on one of the sensor inputs mentioned above.