Weakauras

Weakauras 2 is a World of Warcraft addon that allows the creation of new UI elements (called Weakauras) based on character and combat information.

There are Weakauras that show boss encounter notifications, complementing Boss Mods. However, the most common use case is displaying important information about the player character, for example abilities coming off cooldown or debuffs like Grievous.

The central download site for ready-made Weakauras is wago.io.