Ahead of iOS 13 being announced, Bloomberg reported that a Sleep Mode was coming to iOS and many blogs reported that Apple was working on sleep tracking for the Apple Watch. Bloomberg later said that the feature was removed ahead of the public June beta builds.
A MacRumors reader has discovered the Apple App Store screenshots for the Alarms app for Apple Watch includes text that alludes to an as-yet-unannounced Sleep app. Currently there is no Sleep app or references to a Sleep app in the Alarms app on watchOS 6.0.1 or watchOS 6.1 beta builds.
MacRumors has previously stated that according to an iOS 13 string they have seen the new Sleep app on the Apple Watch will provide users with an overview of their sleeping patterns, as well as send users bedtime and battery charging reminders. Apple Watch users will be recommended to have at least 30 percent of battery life to wear it to sleep.