WowAce

Alternate Power- and Combopoint/SoulShard/HolyPower-bar

Rebuff yourself with the mousewheel.

Keeps track of your current location.

Babble-2.2

Broken in Midnight. I recommend MidnightFocusInterrupt instead.

StatLogicLib

Try on different gear and see their total stats and their differences. In short, an ingame CT-Profiles-like addon.

Manages social information with a focus on main-alt associations.

Checks your gear before bosses and yells at you if you're an idiot

Display front-end for LibGuildPositions-1.0 using HandyNotes

Visualises healing.

Questing minion

Open all your mail

Shows ZoneInfo on the World Map in a perfectly cromulent fashion.

Adds a status to Grid for debuffs applied by Raid Bosses.

SacredBuff

Displays the locations of Garrison music scrolls.

Death analysis tool

Tracks vulnerability debuffs on multiple mobs

Barks at you when you target a crowd-controlled unit