Grid is a nice and very compact UnitFrame, a must have not only for the raiding healer.

On the first view it maybe looks a bit chaotic, but when you get used to it you will be able to get all the information about the player in your group or raid which you will need.

Every little box in Grid represents 1 player of your group. In the center of the box you can see first letters of the playername if the player got full health. If he isn't at full health Grid will display the missing HP. This makes it very easy to find out which player isi in need of healing.

In the 4 corners of every box you can see little dots which can display additional Information about the player status like: Player got aggro, player got a renew, player is shieldet, PoM is on this player ...

If the Player got a debuff which you can dispell it will be displayed in the center of the box as a little icon, so you know you have to dispell and you can see which debuff it is.

Lets get to Clique

Clique allows you to direclty cast specific spells when you click a UnitFrame (a player in Grid). You don't have to target the player and then cast the spell. You can define different spells for every mouse-button and use all the modifiers like alt,shift and control.

My Configuration as example:
left-click: flash-heal
right-click: renew
center-click: Greater heal
button-4: PowerWord Shield
button-5: CoH
ctrl-left: dispell
ctrl-center: PoM
shift-center: Guardian Spirit
shift-left: Binding Heal

if you put all your spells you need for healing on your mousebuttons you only have to move your mouse over the player who needs heal in grid, press the correct button and the player is healed.

You only have to get used to it, because in the begging its hard to remember the buttonsettings.

Links to get Grid and Clique
Grid
GridManaBars
GridStatusHots
Clique