Are cell phone screen protectors really useful? Or are they just a way for the providers to take another $13 from you?
It depends on the protector. The generic thin plastic sheets will probably protect the phone from softer things fingernails scratches and such, but be useless against significant impacts.
Or you could spend more money on a thicker, high-quality protector like the Invisible Shield that’ll pretty much protect it from anything you’d normally have near the screen – you, keys, tables, hard metallic objects, other electronics, whatever. Backed up by a lifetime warranty.
(I don’t work for them; I just became a fan after the first one and I’ve been putting them on all my electronics screens ever since)