Bandlab - Capture, nurture, and collaborate on song ideas in the cloud
Heartbeat - Listen to music with your friends together, on Spotify
Krue - Twitch for music: live streams from amazing musicians
Festify - Festify is a free Spotify-powered app that lets your guests choose which music should be played...
Soundscape - Sync your music with the open source community
BeatSense - Discover great music hand-picked by real people, in a single click. FREE and in real-time!