When a group of teenagers receive an invite to download the latest smartphone app, an intelligent personal assistant, they expect a harmless way to get directions and restaurant recommendations. But the sinister nature of the app soon reveals itself, tormenting the friends by tapping into their darkest fears. As the app exploits the intimate information made available by each of its users, the teens must learn to trust and depend on each other's courage and the limits of their friendship. Once its evil begins to manifest supernaturally in the real world, what will happen if the app goes viral?