Remixatron - Infinite Jukebox on the command line in Python.
Partyhero - Pass your friends the aux!
GoGifApp - Free Slack GIFs App, multiple images to pick from at once
Heartbeat - Listen to music with your friends together, on Spotify
The Eternal Jukebox - For when your favorite song just isn't long enough
TuneMeet - Chat with people who are listening to the same song