Mixed in Key - Mixed In Key is award-winning DJ software that gives you the #1 technique of the world's best...
KeyFinder - Key estimation software for DJs
Tunebat - A browser based song key and bpm database. Supplies compatible songs for harmonic mixing.
foo_bpm - A component for calculating the BPMs (beats per minute) of any tracks in Foobar2000.
TuneUp - TuneUp makes your music fresh and clean!
Tune Sweeper - Show duplicates in your Music library. Automatically select which duplicates to keep and delete based on your preferences. Remove duplicates with one-click from your iTunes or Music app library.