iOS 8.2 will be the first version to officially support the Apple Watch, and so each new developer beta is being carefully scrutinized for any hints about what the watch will do or what its interface will look like. Yesterday, the company released iOS 8.2 beta 4, and users quickly noticed a reference to an Apple Watch companion app in the Bluetooth settings. Today, 9to5Mac has dug deeper and shown us some of what that companion app will be able to do.

For starters, users will be able to customize the watch's home screen from their phones, using a mockup UI not unlike the one used in iTunes to customize an iPhone or iPad's home screen. The Stocks app, at least, will be able to display a single stock persistently on your watch face, and one assumes that something like this could be opened up to other apps in the future as well. Unlike Android Wear, the Apple Watch will support a four-digit passcode to lock the screen—a passcode will be required if you'd like to use Apple Pay with the watch, and the watch will also automatically unlock if you unlock its tethered iPhone as you're wearing it. The full report is well worth a read, although many of the other features (receiving and responding to iMessages and texts, tracking fitness data) is stuff that Apple has already announced.

Our last information dump about the Apple Watch came back in November when Apple released the first WatchKit developer tools. Those tools detailed the screen resolution of both watches (312×390 for the 42mm model and 272×340 for the 38mm model), and showed just how much of the Apple Watch's processing is done on the phone. Presumably to save the battery, the Apple Watch's software will be quite limited in its animations and capabilities. We don't know what the Apple Watch will be able to do when its tethered phone is out of range, but for most activities it will depend on your phone's processor to do the heavy lifting.

The Apple Watch is scheduled to ship this spring, and will start at $349. It will require an iPhone 5, 5S, 6, or 6 Plus.