The application is included in Games. The actual developer of this free Mac application is Mark Noble.
From the developer:
PFMonsterEntryis a simple monster entry for Pathfinder RPG. It is a companion application for PFMonsterPrint (which is coming shortly).
You may want to check out more Mac applications, such as World of Warcraft Interface AddOn Kit or Endarchy, which might be similar to PFMonsterEntry.