HoRNet has released BSharry Key Detector for Mac OS X (the Windows version was released in January, 2015).
BSharry Key Detector was born after the collaboration of HoRNet Plugins and the international DJ BSharry, the tool uses the SongKey technology to discover the key of a song and update the ID3 tags of the mp3 allowing for harmonic mixing.
BSharry Key Detector is available on www.hornetplugins.com for 19,90 Euro.