Sunrizer - basically, a tiny JP8000 clone.

Multi-touch instrument thing.

"DM1 is an advanced vintage Drum Machine. It turns your iPad into a fun and creative beat making machine."

Curious scale-based texture performance instrument.

"Halcyon is named for the mythological bird of ancient Greece, said to charm the winds and seas into a calm during the Winter Solstice. It is a spacial action puzzle game and interactive stringed instrument designed specifically for the iPad." Lovely.