You'll also need to update your iOS app, because you might be prompted to log in to sync your locks. Once that's done (and you're a recognized owner), though, you'll be able to view all the August locks you have on the Watch's screen. If you want easy access to a specific lock, you can even add it as a Watch face shortcut. August Home says it's a different feature from Auto-Unlock, since you'll still have your phone nearby with that one. With this particular feature, all you'll really need is Apple Watch itself.