There is a vortex manipulator toy that was produced that one could wear on their wrist, but it was cheaply built. I'm sure someone could DIY one of higher quality.
You'd probably want to do away with the flap cover though, otherwise you'll have to raise your wrist and the cover just to see the watch.
The Doctor (3rd Doctor, Jon Pertwee cause he's my favorite) took me in the Tardis to the future to get v4 of the Apple Watch. It's so much thinner and lasts for a week without charging.
Even though the vortex manipulator case is cool I don't think I will be wearing one. I want to see the Apple watch in it full beauty. As for making one I'm not sure how easy or hard it would be.