From the producers of “The Purge” and “Ouija” and the director of “Wanted” comes an original thriller where a seemingly innocent prank starts a sequence of events that spirals out of control. “Unfriended” unfolds over a teenager’s computer screen as she and her friends are stalked by an unseen figure who seeks vengeance for a shaming video that led a vicious bully to kill herself. On the anniversary of the shocking suicide, the very same friends who thought there would be no consequences to their actions will find out just how deadly wrong they are. Vitals: Director: Levan Gabriadze. Stars: Courtney Halverson, Shelley Henning, Renee Olstead, Will Peltz, Heather Sossaman, Moses Jacob Storm. 2015, CC, MPAA rating: R, 83 min., Horror, Box office gross: $32,482 million, Universal.