Apple today seeded the fourth beta of an upcoming watchOS 9 update to developers for testing purposes, with the new beta coming three weeks after Apple released the third beta to developers.
To install watchOS 9, developers will need to download the configuration profile from the Apple Developer Center. Once installed, watchOS 8 can be downloaded through the dedicated Apple Watch app on the iPhone by going to General > Software update. To update to new software, an Apple Watch needs to have 50 percent battery life, it must be placed on the charger, and it needs to be in range of the iPhone.
watchOS 9 introduces four new watch faces, including Lunar, Playtime, Metropolitan, and Astronomy, plus it includes updates to some existing watch faces and complications. The ECG app now supports AFib History for tracking how long a person has been in atrial fibrillation.
The sleep tracking feature now includes sleep stages, letting the Apple Watch track when users are in REM, Core, or Deep sleep, and Apple has added a Medications app. The Medications app lets users manage and track their medications, vitamins, and supplements, with reminders when it's time to take them.
Updates to the Workout app add custom workouts and improvements for runners, triathletes, and swimmers. Fitness+ workouts now support streaming to certain third-party TVs for those who don't have an Apple TV, and notifications have been redesigned to be less obtrusive when the watch's screen is active.
Other new features include a CallKit API that allows VOIP calls to be answered on Apple Watch, Apple Watch Mirroring for controlling the Apple Watch with an iPhone, Quick Actions for doing more with a double pinch gesture, and updates to the Reminders and Calendar apps.
