I'm surprised that a found footage horror movie shot exclusively on smartphones didn't happen before Hooked Up. The worst contrivances found footage movies have to justify is why a camera is present and shooting. Having characters shooting video using iPhones they happen to keep on them anyway solves some of that problem.
The image quality of the iPhone is generations beyond the pioneering The Blair Witch Project. Based on the trailer, Hooked Up succeeds as a horror movie filled with blood, jump scares, hot girls, dumb guys, and dirty dark hallways. (Thanks: Twitch Film)
Snyopsis: The story follows two young Americans who go on a sex-fueled trip to Barcelona but things take an unexpected turn when one of the 'hot' girls they pick up turns out to be incarnate of evil.