Apple today pushed the watchOS 9 Developer Preview Beta 2 update (build number: 20R5307h) to Apple Watch users, 16 days after the last release.

To update to the new software, the Apple Watch needs to have a 50% battery charge, must be on a charger, and must be within range of the iPhone.
watchOS 9 introduces four new watch faces, including Moon Phase, Happy Hour, Cosmopolitan, Astronomy, and includes enhanced modern features for several of the most classic watch faces. The ECG ECG app now supports atrial fibrillation history function to obtain important information such as the estimated frequency of heart rhythm showing signs of atrial fibrillation, allowing users to better understand their physical condition. Users will receive weekly notifications about buy ios app reviews the frequency of atrial fibrillation and can view a detailed history in the Health app, including life factors that may affect atrial fibrillation, such as sleep, alcohol intake and exercise.
Sleep tracking now includes sleep stages, giving users more insight into their sleep. The Apple Watch detects whether the user is in REM sleep, core sleep or deep sleep through signals from the accelerometer and heart rate sensors. Users will see sleep stage data in the Sleep app on Apple Watch, see more details such as sleep time, and more metrics, such as heart rate and breathing rate, in the sleep comparison chart in the iPhone Health app.
Apple adds medication app. Allows users to create medication lists, create schedules and reminders, and view medication information in the Health app to help users manage and track medications, vitamins, and nutrients they take. Users can create personalized schedules for each medication and can set reminders to help guide users to take their medications.
The fitness app update adds custom workouts and improvements for runners, triathletes and swimmers. Fitness+ workouts are now supported for streaming to some third-party smart TVs. In watchOS 9, notifications have been redesigned to be less intrusive, yet still functional, and display as a new small banner when Apple Watch is in use.
Other new features include the CallKit API that allows VOIP calls to be received on the Apple Watch, Apple Watch Mirroring for controlling the Apple Watch from the iPhone, more quick actions with the “double-pinch” gesture, and the Reminders and Calendar apps ‘s update.