MAC Users need to download the zip file and extract it to a directory of their choice. Go 2 folders down and you will find one folder called Extensions and 3 files:
If you get a security warning from your machine you need to go to the security settings and select the appropriate option (Run Anyway).
You can use either of the 2 files to open the software. But some MAC users may need to use the KeywordScrubber Dev.fmpur