Watch2Gether - Watch2Gether is an app that allows multiple people to watch the same content simultaneously and interact with each other while watching.
Bandlab - Capture, nurture, and collaborate on song ideas in the cloud
DJ Clique - Listen or watch your favourite content via Youtube on repeat, shuffle or synchronized on all your computers at the same time. Take turns DJ'ing. Enjoy private or public rooms by yourself or together with your friends in sync.
Krue - Twitch for music: live streams from amazing musicians
TwoSeven - Web application that enables people to watch the same thing at the same time across the globe while...
Soundscape - Sync your music with the open source community