WowAce

Tracks Prayer of Mending and changes color based on the number stacked

Shows Item Level and Stack Size in tooltips

StopHealingMobs

Provides help for your daily quests.

Marks ignored players in Grid2 with a color and text notification

Relays item drops to your guild chat.

Adds Auctioneer "bought for" filters to Baggins ("disenchant", "vendor", etc)

LibSimpleTimer-1.0

Show everyone how much you care

BiSList allows you to configure your BiS items list, and keep track of how far you are from them

This AddOn will automatically withdraw all your enchanting vellums from reagent bank.

Mute all sounds except boss emotes and addon sounds

An Addon to make give stock messages based on location or target.

LibQuickHealth-2.0

GuildBankMover

Displays your soulshards in better way.

Invite lots of players in the raid browser for world boss groups

Addon to manage WoW titles.

Nier

Shared handling of media data (fonts, sounds, textures, ...) between addons.