Touch Pianist - Play piano like a pro without playing piano.
IsoPad - IsoPad lets you use your Windows tablet to play electronic MIDI instruments.
Virtual MIDI Piano Keyboard - Virtual MIDI Piano Keyboard is a MIDI events generator and receiver.
TouchDAW - Full-featured DAW control and general purpose MIDI control app.
Pianu - Learn to play the piano in your browser.
Navichord - Intuitive chord sequencer and MIDI controller for iOS