A group of teenage friends are infiltrated by the Red Rose app, which flourishes on their smartphones and threatens them with dangerous consequences if they don't comply with its demands.

School is about to finish for the last time. For many teenagers, this signals the beginning of the next stage of their lives. For a group of working-class friends in Bolton, there is no next stage. The summer stretches out in front of them with an infinite sense of possibilities, but when one of the gang downloads the mysterious Red Rose app, plans change. What starts innocently as a game of admiration rapidly descends into something much darker.—bbc