One of us Is Next by Karen M. McManus

Come on, Bayview, you know you've missed this.

A ton of copycat gossip apps have popped up since Simon died, but in the year since the Bayview four were cleared of his shocking death, no one's been able to fill the gossip void quite like he could. The problem is no one has the facts. 

Until now. 

This time it's not an app, though—it's a game.