WowAce

mHud_Threat

Simple search inspired by vBagnon

FuBar_HBFu

A texture browser for developers and UI modders

Cartographer_Herbalism

Adds tooltip for debuffs (and other things? you found out: no).

SimpleDrumAnnounce

RBM_AbilityWatch

A standalone version of Angry Assignments to create and display personal notes on your screen.

This is an add-on to block incoming guild/party/duel requests (except for friends/party/guild) (previously ASSBlock)

Adds notes to item tooltips

Replacement for WoW's flash/fade functions.

Keeps track of your reagents.

Reports in the Default Chat Frame how many people does not have Well Fed effect, and who are they

"Range finder/display for Discipline's Holy Nova"

Broker add-on for GemHelper

AvionDefaultMedia

Adds Debuff Highlighting to oUF.

Tracks and reports party rolls

Gives equipped and overall iLvl to indicate the quality of a character's gear.