How do we identify and discard energy-inefficient apps? According to two Stanford computer scientists, the solution lies in another app. Adam Oliner and Jacob Leverich designed a program called Normal to tell you which other apps you ought to kill. It’s a telling problem that iOS message boards are plagued by constant complaints of mysteriously drained batteries. But instead of trying to figure out whether your phone is haunted by a poltergeist, Normal uses crowd-sourced user data to show how many minutes of battery life you’d save by exterminating other apps. Normal, as in “is my phone normal?” is the cold, calculating, cannibal of apps. It spares no one. Other than itself, of course.