What can you use your Apple Watch Ultra 4 action button for?

Here's what your Apple Watch Ultra 4 action button can really do, from launching workouts and retracing routes to controlling smart home devices with one tap.

Here&#39;s what your Apple Watch Ultra 4 action button can really do, from launching workouts and retracing routes to controlling smart home devices with one tap.<p><img src="https://www.engadget.com/img/gallery/what-can-you-use-your-apple-watch-ultra-4-action-button-for/intro-1791574824.jpg" /></p>