Apple Watch sleep tracking works closely with the Health and Watch apps on your iPhone. Learn how to turn this feature on, ...

The Apple Watch has ... to access all of the sleep-related features of your Watch and iPhone. (Three of them are on the phone ...

as long as you wear your Apple Watch at night, Sleep++ will use its sensors’ data to build an estimate of your night’s sleep. There’s no need to install an app on the Watch or manually activate a ...