GM Keys is a MIDI capable keyboard that features 128 sounds including pianos, organs and synthesizers. The sounds are compatible with the General MIDI sound set.
GM Keys supports Inter App Audio and can be used as an instrument or a generator with many popular audio hosts. Record, sequence and edit your GM Keys performances in apps like GarageBand, Cubasis, BeatMaker 2 and others.
This app is authored using the Make Audio Apps editor. You can get more information and source code at http://makeaudioapps.com.
This application uses the Fluid Soundfont as its sound library under LGPL license http://sourceforge.net/apps/trac/fluidsynth/
GM Keys is free on the app store: