This app comes bundled with retail versions of Extensis Suitcase Fusion, which I've uploaded separately here:
Extensis Suitcase Fusion 6 v17.3.2 [CORE KeyGen] Font Management App Mac OS X 10.6.8+
Block outgoing connections with Little Snitch
FontDoctor is a professional software tool that locates and eliminates hard-to-find font problems that wreak havoc on Macintosh system performance and applications. FontDoctor has long been the industry standard for font problem diagnosis and repair for publishing and design professionals. FontDoctor will scan your fonts to locate and repair common font illnesses, including missing Postscript fonts, missing bitmaps, corrupt and damaged fonts, font conflicts, and more.
What's New: Updated for compatibility with OS X 10.11 El Capitan