I used a mod in wow 1.0 that showed heals being cast on your target. It required everyone in the raid to have it installed and was broken in one of the later patches. I can't recall what it was called however
I hate bumping ancient threads but I figure it's at least somewhat better than making a new thread... is there a currently functioning addon that does this? I rely on lifeblood oftentimes to prevent my death and this being on a cooldown means wasting it right before I get a heal really annoying. I can't just Focus the healer because being DPS I need to focus the tank in order to keep myself sane while acquiring targets.
I know you didn't specifically mention a raid frames addon, but from personal experience I use Vuhdo to monitor incoming heals, and it works well. It tracks them quite nicely, and it shows them in a simple, efficient way (a shaded bar extending from the right of a depleted healthbar).