Kids these days have reverted to the habits of their great-(great-?)grandfathers, and are wearing pocket watches. Not on vest-pocket chains, and also good for making phone calls and posting "Instagrams" and "tweets" and whatnot...
But most of the time, these devices are in their owners' pockets, and all of them tell the time, usually as (at least a significant part of) their default display: They're arguably pocket watches.