Download of TraktorAutoNextSong 1.2.1 for Mac was available from the developer's website when we last checked. We cannot confirm if there is a free download of this app available. We recommend checking the downloaded files with any free antivirus. The application lies within Audio & Video Tools, more precisely Music Production. The actual developer of this free software for Mac is Anders Fischer-Nielsen.
From the developer:
It's a small tool for automatically finding the next song to play when DJ-ing with Traktor Pro 2. The tool works by creating a weighted graph of every song in a Traktor collection, where the weights determine what song is best to mix into. The weight is calculated using the BPM of the songs and their different keys.
You may want to check out more Mac applications, such as Mandala Virtual Brain, SmallScreen or Nodal CAD Software, which might be similar to TraktorAutoNextSong.