WowAce

Create panels for customizing your UI, sucessor to eePanels

Database of item upgrade IDs

Shaman totem bar

SacredBuff

Provides one or many informational windows with optional interactive widgets.

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

Angry Assignments

Automatically turns on the combat log for selected raid and mythic+ instances.

Collects Herbs, Mines, Gas Clouds and Fishing locations and adds them to the worldmap and minimap

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

Drop the cheapest thing you're carrying

Plugs classical world style fonts into LibSharedMedia-3.0

MendWatch

Detox

Archaeology Assistant

Raid Frames using the oUF framework.

Bulk mail reception made really easy

Display Cooldown Count of Spell Icon and Item

Rebuff yourself with the mousewheel.

Queing of /who and SendWho() queries and a much better interface (see docs), with gurantee to be executed & callback.