Singularity is a DoT/proc/cooldown/Orbs/range monitor for Shadow Priests. It has:
- Timers for DoTs, cooldowns (including the global cooldown), and important buffs (Shadow Word: Insanity and Surge of Darkness)
- Range display for Cascade, Divine Star, and Halo
- Stack number displays for Glyph of Mind Spike, Shadow Orbs, and Surge of Darkness
- Target health display for Shadow Word: Death (by way of the icon being desaturated when your target is above 20% health)
It's also intended to have good default settings, which is to say that you should be able to join a raid right after installing it and do fine without configuring it at all, while also being easily configurable (/singularity, /sng).
Note that this was designed specifically for Shadow PvE; the things it monitors are hardcoded, because Shadow PvE is what I play, and this way the code is kept simple and I'll be able to provide support for everything the addon is supposed to do. It's not impossible that you could rewrite it to work for other specs or classes, or successfully use it below the level cap or in PvP, but you're on your own. I would recommend
EventHorizon for people who want something similar that is more generally usable.