Ability Pulse is an addon that will flash abilities that you use, as you use them.
The intended use for this is for when fraps'ing, or streaming, to make it easy to see what spells you are casting. (this is especially useful for classes which use lots of instant cast spells, such as resto druids/hunters, or when your ui's cast bar has smaller text which might not be legible)
Classes with shorter GCDs, such as rogue, will want to put the total animation length (i.e. fade in time + fade out time + max opacity hold time = total animation time) to less than one second, otherwise the icons will fall behind your actions.
It's pretty much doom_cooldownpulse, with 3 edits in the code, and a renaming, so all credit to Freki of WoWUI for writing the original addon, and thanks to him for helping me butcher it . I'm absolutely awful at coding, so the addon is pretty messy for what it's intended, but it works. Anyone more experienced with lua is welcome to rewrite it lol.