Type /tauntmaster or /tm to open the customization menu. You may also click the new minimap button.
TauntMaster is a threat-management addon. It automatically displays a button/healthbar for every member of your party or raid.
If the party/raid member begins to gain more threat than the tank, their button turns yellow.
If they begin to insecurely tank, it turns orange.
If they are securely tanking, it turns red.
If another party member gains aggro, simply click their button and TauntMaster will automatically taunt their target off of them.
Taunt Master is pre-programmed to cast the following taunts on the target of whichever group member you click:
Death Knight:
Left Click: Dark Command
Right Click: Death Grip
Druid:
Left Click: Growl
Rigth Click: Challenging Roar
Paladin:
Left Click: Hand of Reckoning
Right Click: Righteous Defense
Warrior:
Left Click: Taunt
Right Click: Mocking Blow
Shift-Left Click (also Alt-Click & Ctrl-CLick): Challenging Shout
Shift-Right Click (also Alt-Click & Ctrl-Click): Intervene
Note: TauntMaster can only taunt the group member's targets (unless of course the taunt is a mass taunt like Righteous Defense, Challenging Roar/Shout, etc. in which case it will successfully taunt whichever mobs are attacking your group member). Blizzard's API does not allow an addon to directly taunt a target that isn't being targetted.