So I was talking on the phone while playing Hill Climb Racing when I minimized everything and opened up clean master to kill any additional applications which might be taking up battery. As soon as I killed the tasks and pressed the back button, the phone suddenly froze and the screen stopped taking any finger responses. I pressed the power button, the phone went into sleep mode and stopped taking any power button/volume button responses. After 5 mins, it restarted on it's own and now both the games on my phone i.e. Hill racing and Temple Run are lagging a lot. They were ultra smooth till now. Overall, the phone still seems to be non laggy but im still concerned. Any advice?