Ui question

Ive seen many peoples who UI's actually come up with an icon flash in middle of screen saying so and so totem or buff up or failing or coming off cd. What is this called. I think it would be nice to have this now that i can add tons of addons to my toons, and not worry about fps issues ne more.

Personally I have this functionality in Mik's Scrolling Battle Text, but I know the one a lot of other people use which has the big icon pop up is something else, which I have not tried myself, and don't remember the name of at this time.