In case you were wondering if there were any new theremin apps available, there are, EasyTheremin is here and it's free

So, here's  the detail ...

A theremin in your pocket! Using your iPhone's gyroscope, this app allows you to control pitch and volume of a simulated theremin sound. Hard mode is just like the real thing, and easy mode allows you to play in any standard Western key. The "tonal compass" allows you to see which pitch you're playing.