WowAce

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

Allows combined aura detection. motw + gotw, all 4 mage int buffs, etc. in one status.

Bars showing amount of buffstacks

DebuffEnough

A frame with a text that gives you the amount absorb left on target, or in TankMode absorbs left on yourself.

Calculates incoming damage avoidance and mitigation

Spell overlay customization and spell state HUD.

Adds aura indicators to unit frames

Provides extended aura status settings.

Shows a countdown bar for the duration of auras (e.g. HoTs, DoTs)

Assistance for the Ra-den encounter. (Unstable Vita order, ball kill order)

EBB-inspired buff bars with click-to-remove support

A raid buff tracker

Audible Alerts for self-gain, self-lost, any-gain, all-lost of statuses.

SalvationKiller

Provides training reminders to help decipher the Blizzard Spell Alerts.

Keeps track of important de-/buffs in a splash screen

Smooth combat HUD based on ArcHUD2

Holy Power, Shadow Orbs, Rogue Combo Points and Monk Chi.

Filters unimportant Buffs.