Minecraft crashes randomly on my android phone and now my sisters android tablet.

Sometimes Minecraft PE completely crashes the hardware requiring removing the battery to reboot the device. All that happens is that the game freezes and the entire system becomes unresponsive. I mean everything. I cannot turn the power off via button. I cannot do anything on the device. This can happen when we are doing anything. You could just be roaming a field and then BAM crash. It makes me not even want to play it because I have no idea what to do when it happens on hers because it has no removable battery.