With 24 days left on its Kickstarter, AUUG Motion Synth enables one to “Transform your iPhone or iPod touch into an intuitive and expressive motion-controlled musical instrument” via createdigitalmusic.com:
Transforms your iPhone or iPod touch into a new kind of musical instrument.
Lets you play notes and alter their sound through motion.
Can expressively control a vast array of sounds on your iPhone or iPod touch by ‘playing’ other audio apps.
Allows you to intuitively shape vocal harmonies and effects in real time by controlling harmonizer hardware devices or effect apps.
Can wirelessly control software on a laptop or desktop computer.
Can control non-wireless music hardware via MIDI cable.
Will allow you to design your own forms of motion-based sound control, and share them with others.
Is compatible with iPhone (4S and up) and iPod touch (5th generation and up).