screen protectors are the BIGGEST waste of time. They make your device look crap and do little in protecting.. Besides the glass is highly scratch resistant and the back does a good job too.
My old 5, was only in a bumper, with exposed glass and back.. Given the bumper slightly elevates the back or glass when resting face down. Unless you go doing something stupid like throwing it in your pocket with keys, or other sharp objects, you'll never need those screen protectors.
Never ran with them after the 3S. Never ever even rec'd even so much as a hairline scratch. Mind you, I am careful, but not that careful.