WowAce

A popup menu containing user-programmable scripts.

Manages the SavedVariables of your addon with a layered hierarchy of settings.

Replacement for default Rune Frame and more.

Saves contents of your guild bank and sends/receives updates over the addon channel

Clean looking square minimap with many options.

Makes those pesky garrison animations go away.

Manufac

Auto sizes frame layout depending on group/raid size or predefined zone data

Crowd-control monitor

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

FuBar_ItemDBFu

Monk Brewmaster/WindWalker Priority and Buff/Debuff Tracking Tool

CharScanner scans Basic Character Data, Talent Specifications, Equipment, PvE/PvP Achievements, PvE Boss Kill Statistics and ...

SpyGnome

MiniPet, Always keep your little companion with you, based on the work of Carra.

Lets you drag UI frames around

GemCensus inspects people and records which gems they have socketed. Then displays which gems are the most popular.

LDB data source for Tradeskill Cooldowns

CombatLog in SimpleCombatlog style

Allows you to loot BoP items without prompting when not in a group or raid