COSO killed my phone. For a day. This morning, I was usong the COSO app on my phone, was looking a 6-panel graphic attachment. To a post when suddenly my screen froze, would not accept touch input. The buttons all still worked but not the screen. I couldn't restart/shut down cos even that requires touching buttons on screen. So I had to let the battery run down to 0%, which took all day; that was the only way to restart it. Recharging from 0 was pretty fast, only took about an hour.