AMPLI.FI - Live online music community. Twitch for tunes.
Aftertouch - Aftertouch – 3D MIDI Controller created and published by Kevin Nelson.
Krue - Twitch for music: live streams from amazing musicians
SoundGrail - SoundGrail Music App designed for pianists, guitarists, and DJs.
Soundscape - Sync your music with the open source community
keezy - A colorful soundboard. Play with music.