With this app, you can measure the heart rate easily.
After tapping "start button", the average heart rate will be displayed in the uppermost frame by tapping "heart button" at every one beat.
The heart rate about last one beat will be displayed in the second frame from the top.
In the measurement of exercise intensity (add-on), the screen change to the dark and the exercise intensity will be displayed in the second frame from the top.

Karvonen method — the exercise intensity take 0% for the resting heart rate, take 100% for the maximum heart rate.
Zero to peak method — the exercise intensity take 0% for 0 bpm heart rate, take 100% for the maximum heart rate.

*The default values of the resting heart rate and the exercise intensity from age and sex should only be considered as a guide.