FontPrep 3.1.1 for Mac was available to download from 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 Fonts. This free Mac application was originally produced by Brian & Matthew Gonzalez. 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.
From the developer:
FontPrep is a missing font generator for Mac OS X. The app takes your TTF and OTF font files and generates all of the respective font-formats for the web: WOFF, EOT, and SVG. The app allows you to take a font with thousands of characters and create a font with 1, 10, 67, 100, or however many glyphs you need.
You may want to check out more software for Mac, such as fontplop, which might be related to FontPrep.