There are restaurants right now where you can go in, order from a "kiosk" at the booth or table, then pay for your meal on said kiosk with your smartwatch, never having to so much as pull out your wallet.
Actually I can't. Don't go to any such restaurant or McCrap. Don't have, don't want, don't have use for any such device.
I have been (slowly, it seems) getting back to the habit of cash. I am much more aware of what I have spent.