Short description of Stop-the-Pop-Up 2.54: Kill browser, Messenger Service, GAIN and SaveNow pop-ups automatically. The popup stopper has full support for both pop-ups and pop-under ads and will kill them even before they appear on the screen. Each time a pop up is closed you will hear a cute sound effect. To allow pop-up windows you can temporarily disable the pop-up killer by holding Control, Shift or 'a'.