HM Apps are add-ons to the base Holdem Manager 3 software.
NoteCaddy takes automated notes for you allowing you to view player tendencies based on Bet Sizing and many other factors.
Ignition Hand Grabber
Ignition Hand Grabber allows you to import hands into HM3 from the Ignition poker site.
TableNinja is a hotkey program that allows you to play more tables with less effort.
Leak Explorer finds leaks for you based on all the players in your database.