WowAce

Library providing mappings between trade skill recipes, spells and created items

Auto repair + shows durability.

Adds countdown voices from Heroes of the Storm to BigWigs for all supported locales.

Additional information about player spells.

Keeps track of quests.

QuestLog

Alternate Power- and Combopoint/SoulShard/HolyPower-bar

Track time played, rested XP and money for all characters

Bayi's Extended Questlog

MorgDKP

A blizzard group finder replacement

Enables multi-line/unlimited-length pasting of text or commands into WoW

Adirelle's unit frames, based on haste's oUF.

A simple combat log that displays events similar to SCT

tracks and share quests between your party

Find five Ephemeral Crystals, get a pink hippogryph

Displays Instance Maps

Provides access to all Portal and Teleport spells on right click of one button.

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

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