SongMine - Songmine is a free online tool for discovering and recording chord progressions with your favorite DAW.
BandNext - Discover bands that sound similar to artists you already love with BandNext. A single click saves your results to a Youtube playlist.
Blocs Wave - A free audio app for creating music loops.
Gnoosic - Even if you don't know what you are looking for - gnod will find it.
Helio - Design successful products by revealing key user behaviors
TasteDive - TasteDive recommends similar music (musicians, bands), movies, TV shows, books, authors and games, based on what you like.