Songlink - Share music with anyone.
BandNext - Discover bands that sound similar to artists you already love with BandNext. A single click saves your results to a Youtube playlist.
humit - A social networking app for music sharing and discovery.
Musicroamer - A visual Pandora for discovering new music
aux.app - A free web-based music platform to play music from other popular online streaming services.
stats.fm - With the click of a button you'll be logged with your Spotify account and you'll instantly gain access to a valhalla of cool stats and insights.