WowAce

Don't underestimate your little critters!

Shows optimal target to use various area healing spells

Warnings about tanking specific abilities

DogChow

Create reagents easily

Relays item drops to your guild chat.

Automatic tracking of the current target's creature type. For the discerning PvE hunter.

Allows you to create icons, which can be customized greatly by user's input. CiR is more than just the usual cooldown tracker.

Tells you who bought your auctions.

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

Helps you keep track of your experience.

Simple loot specialisation display with selection in tooltip.

GotWood

FelwoodFarmer

Allows the user to customize the the tooltip with lua-scripts

SpyGnome

FuBar_KTMFu

Adds notes to item tooltips

FuBar_FuXPFu

lern2count adds ABinfo castcounts to spell and actions. It has a builtin reagentcount too.