WowAce

ERP

RaidHelper

DelMapa

A seperate focus bar, with focus gain prediction and rotation forecast.

Adds your damage to Scrolling Combat Text

RS_ClassColors

Welfare Epics

Protractor

Shows the price of a single item in the Auction House.

Avion

Puts a timer in /yell when you get Unbound Plague during the Heroic Professor Putricide encounter

A 'channeling spell'-tracking addon for Affliction Warlocks. Drain Soul, Drain Life/Harvest Life and Malefic Grasp.

Prospecting and Disenchanting Aide

Simple, nice-looking power bar addon for all classes.

vChat

A raid buff tracker

Adds indicators to the sides of Grid frames.

TrackingInfo

Test whether the player can really dispell a buff or debuff, given its talents.

Toggle Windowed Mode with click or keybind.