The problem is, it was basically useless. The main use case for heart rate monitoring is continuously throughout the day/night, or during exercise. A watch is very good at this. An optical sensor on the back of your phone is not.
Periodically checking your heart rate by holding your phone in a specific way is not a useful feature for that many people.
+1. If a phone has a stopwatch, you can get your bpm at a given moment with a finger and a multiplication (or patience). Given the limited real estate on a mobile phone it's crazy to devote any space for something so trivial.
For me, just having something that you can check 1 time per year is much better than nothing. The anecdote: I was working two heavy manual labor jobs 7 days per week and felt absolutely fantastic, glowing with power. Turned out the heart rate at rest was 180 lmao. Like a rabbit. Took a few days off, it dropped below 70.
It should decline some 60 sec after physical activity. I think I measured after 10-15 minutes. Fatigue, dehydration, lack of sleep, a diet with lots of coffee. I just added those to the todo list. I went home to sleep (and confiscated the heart rate meter), the next morning it was around 100 bpm which is still terrible shape. Over the day it sunk to 80, over the 2nd day to 70, 3rd a bit lower. Back at work it would barely elevate. The moral of the story: Don't work out 11 hours per day for 6 months straight.
The problem is, it was basically useless. The main use case for heart rate monitoring is continuously throughout the day/night, or during exercise. A watch is very good at this. An optical sensor on the back of your phone is not.
Periodically checking your heart rate by holding your phone in a specific way is not a useful feature for that many people.