This weakaura displays a short info about the remaining cooldown, whenever you try to cast a spell which is on CD.
It can basically work as as simple all- in-one solution for your combat & rotation relevant spells.
Per default every failed spellcast will be shown, so there isn't really much to setup.
Position, size, alpha,…. for the visual alert can be adpated to your liking.
Added a blacklist feature, which can be used to ignore certain spell IDs.
Fadeout timer for the icon can be set in custom options.