I play a lot of idle games all day where i just need to tap the screen once every 3 minutes or so, but those games drains battery life. Is there an app that turns it off shortly after a tap and turns on when i tap it again without locking it?
Nope. Unfortunately the screen-off access for 3rd party apps and even launcher activities require the system to be locked after a screen-off command. The only way this can happen without locking it is by using the stock standby timeout (which some phones allow you to customize to whether or not to lock the device upon screen off or with the power button).