Partyhero - Pass your friends the aux!
RightGIF - Less noise, better GIFs. A better /giphy for Slack.
Heartbeat - Listen to music with your friends together, on Spotify
VixT on Slack - The best video mashup app now on Slack.
TuneMeet - Chat with people who are listening to the same song
Slack Meme Bot - Spice up your team conversations with memes