Parallel - Listen to music with friends over Spotify at the same time
slack-fm - Self-hosted service to sync Last.fm with your Slack status
Join My Playlist - Listen to music live together with your friends in Spotify.
Slack Status Icons - A custom set of status emojis for Slack
TuneMeet - Chat with people who are listening to the same song
JQBX - turntable.fm for spotify