There's quite a few, I personally also use Quick Settings.
I've downloaded a couple others as well but, really don't like them. Where as Quick settings, does that and more. You can change the brightness, turn wifi on/off as well as bluetooth. Maybe does more than you want but, it's unobtrusive. You can set it so it shows an icon in the notification bar, or only shows when you pull the notifications tab down (which is how ive got it set).