Festify - Festify is a free Spotify-powered app that lets your guests choose which music should be played...
Parallel - Listen to music with friends over Spotify at the same time
Twinjack - Stream Spotify music with anyone with just a link
Slackbox - Spotify playlist collaboration through Slack
Join My Playlist - Listen to music live together with your friends in Spotify.
aux.app - A free web-based music platform to play music from other popular online streaming services.