Apple today seeded the fourth beta of an upcoming watchOS 7.4 update to developers for testing purposes, with the new beta coming two weeks release of the third beta and over a month after the launch of watchOS 7.3 with "Time to Walk" functionality, expanded ECG availability, and a new Unity watch face.
To install the watchOS 7.4 beta, developers need to download the proper configuration profile from the Apple Developer Center. Once the profile is in place, the watchOS 7.4 beta can be downloaded through the dedicated Apple Watch app on the iPhone by going to General > Software Update.
To update to the new software, the Apple Watch needs to have 50 percent battery life, it must be placed on the charger, and it must be in range of the iPhone.
Alongside iOS 14.5, watchOS 7.4 introduces a new "Unlock with Apple Watch" feature that lets an iPhone with Face ID use an unlocked and authenticated Apple Watch as a secondary authentication measure when you're wearing a mask, alleviating the need to enter a passcode to unlock the iPhone.
Face ID does not work when wearing a mask, but this new Apple Watch feature provides an easy but still secure way to access the iPhone without the hassle of a passcode. It's similar to the Apple Watch unlocking on Mac and can be enabled in the Settings app under Face ID & Passcode.
An unlocked Apple Watch paired with Face ID can unlock the iPhone when a mask is worn, but it's only for mask usage. The Apple Watch cannot be used to authenticate Apple Pay or App Store purchases, nor can it be used to unlock apps that require a Face ID scan. In these situations, the mask will need to be removed or a passcode/password will need to be used instead.
When the Apple Watch unlocks the iPhone, you'll feel a haptic tap on the wrist and will receive a notification on the watch, similar to how it works when using the watch to unlock a Mac.
For those who use Apple Fitness+, the watchOS 7.4 update combined with iOS 14.5 and iPadOS 14.5 enables AirPlay 2 for Apple Fitness+, so workouts can be streamed to an AirPlay 2-enabled TV or set-top box. Apple Watch metrics do not show up on the screen when AirPlayed, however, and that feature is limited to iPhone/iPad/Apple TV.
Apple has said that watchOS 7.4 will be released in the early spring, with spring set to start on March 20, so there are still a few weeks of beta testing expected.
