This is really nifty.
It’s been trending around Twitter, and someone discovered that if you wrap your Apple Watch around your iPhone, open the Camera app on your Apple Watch, have the Camera app open on the iPhone, switch the iPhone over to Video, and this allow the Apple Watch to be used as a viewfinder for the iPhone’s back camera.
The video might describe it better:
Take a gander and let us know about your experience in the comments.
Via Apple Watch hack