You might have seen expensive phones come with a heart rate measurement capabilities. Samsung uses some proprietary tech for the heart rate measurement. But to do that on any phone it just needs a rear camera and a flash accompanying the rear camera.
For this, you need to download the app on your Android phone called Heart Rate Monitor. The app is quite simple in working and doesn’t have many options to confuse you. It obviously records the measurements and you can also tag them, like “After workout”.
Download link: Play Store
You can also set the timer for which it will measure the heart rate. More the time of recording, higher will be the efficiency and by default, it comes with a setting of 15 settings. Do note that, it does not show Blood Pressure or BP, it just shows the heart rate or Beats per Minute.
Now coming to the measurement, just place one finger on the phone that it covers both the flash and the rear camera. The flash highlights the blood vessels and the camera records the beats.
There is an option in the settings in which the app produces beeps when it records the beats. This is the way I was able to check if the recordings are true, and they are.
I checked my pulse on my arm using my thumb, which is the normal procedure to check pulse, and the pulse was in sync with the beeps produced by the app. Which means the readings are true.
But I would like to tell you that this is just for a personal reference and is not intended to use for any medical purpose or emergency. These readings should not be trusted for any medical operation or medication. This is just a fun app, which also shows a reasonable level of legitimacy.