An addon for the WoW Vanilla client (1.12.1) that keeps track of the number of Shackle Undead debuffs that are up on Guardians of Icecrown during Phase 3 of the Kel'Thuzad encounter.
It will broadcast them to /rw if you are leader of the raid or promoted (i.e. ">>> 1/3 SHACKLES UP <<<"). If you are not, it will show them to you in your own error frame at the top of the screen.
/ktshackle to turn the addon on or off.