Progy shows class related procs like Hot Streak for a Mage or Killing Mashine for DKs.
Progy will give you a list of possible Procs for your Class and spec and each one can be activated/deactivated.
Furthermore four more induvidual Procs can be defined by simply typing in the Name of the Buff.
Activated Buffs are shown by the bufficon in a configurable frame wich can be changed in size an alpha level.