Samsung Health as one of the best all-around health apps – for me. It is impressive to see how far it has come over the years with one catch – the latest version requires iOS or Android 9 or later.
The heart rate monitor (HRM) is different from the Gear S3. It has a single green LED and four photodiodes for the best accuracy. Its automatic HRM (Always, Frequent or Never) is first class and as accurate as an external monitor or chest strap. It can also sense stress. It will not work if swimming as it requires skin contact.