This software bills itself as functional, but is anything but. It will leave your id3 tags a mess, and it won't even correctly add BPM data to all of the files it damages. Don't even think about looking for a support forum, FAQ or list of common problems, either... Because there aren't any. Don't even hope that they'll respond to your e-mails. It didn't happen for me, and there's nothing to suggest it will happen for anyone else. I'd say use Windows via Parallels and run MixMeister for a better solution. Anything but this.
1) Some files had their artist, album, title or genre field jumbled up (e.g. Android would become something like nArdiod). Sometimes it was all four fields, sometimes it was one. It's been a month or two and I'm still finding these occasionally.
2) Some files that had BPM data previously were left with no BPM data at all.
3) Demo version over-writes comments in your tags saying that the BPM was determined by BPMer, and the pro version neglects to remove these. I hope you don't keep anything interesting in your comment tags if you use the demo version.
4) The log file is almost entirely useless. BPMer told me there were errors but the log only had a list of every file scanned followed by "updated", "up-to-date" or "filtered due to genre". No error messages to be found.
This is not the software you're looking for.