WowAce

EBB adds groups of bars to your screen showing you which (de)buffs currently affect your toon or some other units.

Bayi's Extended Questlog

Watches your chat, flagging missplled words, and offering correctly spelled suggestions.

Incubator

Questing minion

tracks and share quests between your party

Display aura information inside action buttons

Show the appearance of an item when you mouse over it

A simple combat log that displays events similar to SCT

Reports in raid chat whenever a raid member "fails." /EnsidiaFails to configure.

DKP system for all guilds in the Banana Republic.

Adds countdown voices from the heroes in Overwatch to BigWigs.

FlexBar2

Show buffs on nameplates.

Co-ordinated targetless Party and Raid wipe recovery. Evolved

Adds a status to Grid for debuffs applied by Raid Bosses.

A blizzard group finder replacement

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

Keeps track of HoTs, DoTs, Buffs and Cooldowns. With audio and text alerts to refresh them.

Alternate Power- and Combopoint/SoulShard/HolyPower-bar