Momixa - Pick two songs and get the perfect mix
MusicTwin Finder - Find your MusicTwin by your Spotify playlists in 5 seconds.
FIEND.fm - "Hot or Not" for music discovery: 2 hrs of tracks in 2 mins
Symphona App - Designed to make orchestral staff management a breeze.
Pacemaker - Create and share mixtapes with friends
JamBuddy - Find and collaborate with musicians around you thru Spotify