Apple's smart watches may be able to recognize arrhythmic heart rates using its ECG function but they may have slept late another neat feature: sleep tracking. The manufacturer based in Cupertino is currently working on making improvements in this area. However, apple watch customers will have to practice patience till 2020 for this new function.
https://www.notebookcheck.net/Slept-late-Apple-Watch-will-include-sleep-tracking-feature-in-2020.410970.0.html