The World Health Organization (WHO) states that washing your hands for 20 seconds is vital for stopping the spread of Covid-19 and so Apple uses the Health app on the iPhone to show the frequency of hand-washing and will let the user know if they haven't washed their mitts for long enough, whilst also reminding them to clean their hands when they return home.
The high-tech wearable also uses motion sensors and the device's microphone to detect movement and the sounds of hand-washing.
A press release states: "In a first-of-its-kind innovation for a wearable, Apple Watch uses the motion sensors, microphone, and on-device machine learning to automatically detect hand-washing motions and sounds.
"It then initiates a 20-second countdown timer, and if the user finishes early, they will be prompted to keep washing. Apple Watch can also conveniently remind the user to wash their hands when they return home.
"The Health app on iPhone will show frequency and duration of the user's hand-washing, as well as information on the importance of hand-washing, as it relates to overall health. Sounds used to detect hand-washing are not automatically recorded or saved by the Health app or Apple Watch."
The new watchOS 7 update also sees sleep tracking added, which measures quality of sleep, movement, heart rate, and even noises like snoring.