I've just got an Android tablet on Freecycle. It's on Android 4.0 which I know isn't the latest, but when I try to update it from the settings I'm told it's up to date. I've been reading about custom OS images but I have no idea which one to use or which ones are even compatible. Can anyone provide some guidance? It's a 'CNM Touchpad 7' if that makes any difference. Thanks in advance!