Everything OK with Mountain Lion! I recommend it.
What for do I need this tool? I can read NTFS volumes under my OS X 10.7 without any additional software. There is a problem to write on NTFS volumes under Mac, it can easily be solved with the help of Paragon NTFS for Mac.
Its not working with OS X Mavericks and Yosemite(Beta).Don't install because after installing you will not able to read any NTFS.
I can verify that NTFS-FREE works fine at first - but for larger drives it simply crashes the system. The limit seems to be around 1.5-2TB. Also there is no way to uninstall it (unless you know how to track down kext files and removing them manually) Stay away unless you're sure you can clean up the mess it leaves behind - my recommendation for ParagonNTFS stays.