Apple Watch Series 5 or 6 could come with a feature rivals have supported for years

You can track your sleep on existing Apple Watches, but only by using third-party apps

As hard as it might be for Apple's smartwatch market competition to catch up to the life-saving technology enabled on the Series 4 not that long ago, companies like Fitbit and Samsung are actually well ahead of the Cupertino-based tech giant when it comes to a feature many wearable device owners probably consider to be quite useful. We're talking about sleep monitoring functionality, which has been present on low-cost activity trackers from Fitbit or ...