Shin Megami Tensai the Hero Summoning saga

Izuku and his childhood friend Hibiki Minegishi wanted so desperately to become heroes and go to UA High, but tragedy struck the boys finding out they were quirkless so they were targeted for bullying. By the age of 10 both boys got their own cell phones and took a slight interest in the occult and used it to escape their miserable lives other than video games. They found a app that could presumably predict someone's death, and a freak accident predicted by the app caught the two boys like deer in headlights. Now they use monsters presumed to be evil for the forces of good.