Automatic power cut off for stove
I know this already exists for elderly people and people with bad memory: a timer for the stove.
I think it is a good idea for every household. Just press a button at the wall and the stove is powered for 1, 2 or 4 hours; should be enough for most cooking.
Never be afraid of having forgotten the stove turned on again.
The power cut off can (of course) be overriden when need arises.