WowAce

A library to help with localization of item types and subtypes.

A collection of Rogue modules.

Am I locked out? - Displays all RaidIDs for all chars

Show all the leyline taps in Suramar

Food/water macro generator

Tooltip of awesomeness. Moo. It'll graze your pasture.

Libra

Improved Questing Experience

Tells you if you're buffed

Keeps account of attendance and loot for raids, parties, bgs, arenas and solo for questing.

Manages social information with a focus on main-alt associations.

Allows the user to preview and track their progress in the collection of various transmogrification appearance sets

Show all the orbs for triggering Kosumoth

Displays the locations of the chests for the Treasure, Treasure Everywhere achievement

A replacement tradeskill window for Classic

Show what quests have changed

Shows you a much bigger icon selection frame

Try on different gear and see their total stats and their differences. In short, an ingame CT-Profiles-like addon.

Death analysis tool

Smart raid loot and DKP tracker with automated standby and learning