WowAce

Shows simple Buttons for your Cooldowns :)

Allows the user to preview and track their progress in the collection of various transmogrification appearance sets

Visualises healing.

Omnibus

ArcHUD2

Tracks, transmits and displays the cooldowns of your raid.

Inspects all members of raid and saves in database, as well as lists people's dkp values

Teleporters in Suramar? Sure, why not?

Shows where the equipment of inspected users or yourself is from.

Does stuff for sachmo

A library to help with localization of in-game subzone names.

Displays online guild mates.

QuestLog

Keeps track of current money and all your characters on one realm.

HUD that you can tweak the way you want.

View an image of your guild vault from anywhere.

Shows skills in a tooltip and allows them to be used.

DogChow

LDB display of currencies, gold totals and session / daily / weekly statistics for all characters on a server.

Checks your gear before bosses and yells at you if you're an idiot