The simplest yet most effective and accurate!
After trying at least eight different apps to measure heartbeat and zones in my Apple Watch I settled with this one as the best by far. I use other things like a Whoop to track my fitness so all I wanted is an app that displays in big letters on the watch the heart zone and the heartbeat. All you need is 2 taps no complications no sweat great accuracy and works with external Sensors! The heart rate is displayed really fast no waiting time like the native Apple Watch heart.