KAnnounce

While there are many addons out there that will put messages in chat channels when you personally cast a spell, there are few that will put events into chat channels no matter who casts them. Furthermore, when everyone has their own specific announcing addon, the messages aren't uniform and might output to all the wrong channels. This addon is designed for the raid leader/heal officer that wants to output CD messages to chat, or report in a channel who is interrupting what (in case you're having a problem with Release Aberrations, for example.)

By default, only some raidwide CDs and healing CDs are announced and only to the Chat Pannel, but you can easily add whatever spells you want and announce to mostly any channel you want.

This addon is not as extensive as an addon like ThatJustHappened, instead, simplicity is preferred here over customizability.