"Happyliltree is my BFF" lets you put raid icons on your party members with a single action. The large and colourful marks allow you to keep track of them in crowds. It uses circle, diamond, triangle, moon and star. It won't affect skull, cross or square.
It can be keybound in the keybinding section under Addons > Happyliltree is my BFF.
The slash command is /bff so you can put it into a macro and onto a button.
The one action will toggle it on and off.