Download of FolderWatch 2.0.5 for Mac was on the developer's website when we last checked. We cannot confirm if there is a free download of this app available. The program lies within System Tools, more precisely File Managers. Please check the Mac app with an antivirus before launch as it is downloaded from the developer's website, and we cannot ensure that it is safe. This software for Mac OS X was originally developed by brothersroloff.
From the developer:
FolderWatch only copies differences between the source and destination folders, saving you time and bandwidth. The heart of the application is powered by rock-solid rsync technology.
Save disk space by filtering out certain file types, directories or individual files.
You may want to check out more Mac applications, such as Kollaborate Folder Watcher, which might be related to FolderWatch.