Playlistful - Collaborative playlists for parties!
Fiestah - Get quotes for event needs, and pay all in one place
Spotalike - Spotify playlist with similar songs, according to Last.fm
Party with a Local - Party with a Local is a free app that connects travelers with locals that want to party.
Party Time - Your personal clubbing concierge
Clearbit for Slack - Send all signups directly to a Slack channel