WowAce

Tracks the precise arrival & departure schedules of boats and Zeppelins around Azeroth and displays them on the Mini-Map and ...

Shows a window displaying any raid member below 10,000 health during the Chimaeron encounter.

Numen

Displays the time until the next battle and more.

Save and send chat messages to many channels. Allows quick item and profession linking within your messages.

Considers an item against all the items you have to determine whether or not it is an upgrade

AceBuffGroups

CraftList2

Customize the PlayerPowerBarAlt display

HunterAEP

Provides the ability to suppress specific spellcasts like "Deaden" from your casting bars.

Add a line to herb tooltips that shows what pigment they produce.

Communicates with guild members for their positions on the world map

SanityItemCache

Augmented Virtual Reality. Draw and add markers in the 3d world.

Monitors the combatlog identifying players from the oposite faction near you.

Lets you drag UI frames around

SinkLib

Watch tooltip updates to announce when you find specific objects

Adds Friend and Guild options to the context menu of player units.