MuTheremin iPad App Demo
The following demonstrates MuTheremin iPad App version 1.0. It’s a multi-touch theremin inspired synth and it’s free.
Pros: Free, Multi-Touch,cool lights
Cons: It’s buggy. You will hear clicks and noise. I used an Alesis IO dock for audio. Also tried it though headphones. Same problem.
More info here http://ipadloops.com/free-mutheremin-ipad-app/