WowAce

FuBar_ChatAlertsFu

Monk Brewmaster/WindWalker Priority and Buff/Debuff Tracking Tool

Displays information about the current zone on the World Map, for WoW MoP Classic

Rep2 displays a message, which shows how much reputation you gained, and how much is needed until the next standing.

Keeps track of healing spells cast by everyone in a group.

StatStain

Add-on that allows you to setup and quickly switch between different profiles of your action bars

GridAlert

Raid level alternative player power warning (Atramedes, Cho'gall, Lord Rhyolith)

Replacement for default bags.

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

Provides a quick display for the LFG Call to Arms

Aura alarm.

Client for MagicDKP which handles standby calls and bidding on items.

Automatically leaves the global channels when inside an instance/raid and restores them when exited.

A fully featured library tracking all ongoing absorb effects

aUF_RangeCheck

Quest helping: fetching items to use, that sort of thing.

Resizes some default UI frames (GuildUI, LootFrame, RaidInfo, TradeSkillUI and TrainerUI) to show more lines

TableTopLib