Undrtone - Social layer on top of Spotify and Rdio from Scott Vener
TubeLister - Generate a YouTube playlist from your opened tabs.
PlaylistMap - Connect with Spotify playlist curators from around the world
Vidlis - Create music playlists from YouTube videos.
BeatSense - Discover great music hand-picked by real people, in a single click. FREE and in real-time!
Tuned Rocks📺 - Discover🔎 curated Youtube videos 24/7