“Don’t Hang Up” (2017) is an absolutely derivative horror movie that nevertheless manages to be halfway decent.  I’d rate it a 7 out of 10.

We follow a handful of older teenage boys whose favorite avocation is perpetrating cruel prank phone calls and then posting them on the Internet.  The horror genre’s penchant for vengeance should make their comeuppance predictable.  “Don’t Hang Up” seems to borrow in equal (large) measure from the “Saw” and “Scream” film franchises, with touches of “Unfriended” (2014) and even “Silence of the Lambs” (1991).

Still, this was a halfway serviceable scary movie.  There were nice moments of tension, and it held my interest.

This doesn’t belong on anyone’s must-see list, but it’s a fun enough time-waster if you can’t find a better movie.