I have never seen such.
However you "may" have found a legitimate use for a "smart" watch. You could load the Roku remote app on it and use it to control your Roku.
Yeah but then where would I plug my headphones into? The smartwatch? Don't even think about bluetooth earphones because the audio delay would be too great when watching a TV show.
Using the audio port on the remote gives a very slight delay in the audio. A bit annoying but you get used to it after a while.