[Lactobacillus]

I do not know if this helps you but there is an app called "Instant Heart Rate" on Google PlayStore.

"Instant Heart Rate" app works on my BB Classic. It only needs only an Android phone that has a flashlight and camera side-by-side so that is a good start. It also has a higher rating than Kardia and was apparently voted the best health app in the UK.

I have done only a quick test: "Instant Heart Rate" takes a long time to boot up and it might drain battery. The reading seems very accurate. The default settings cause the app to close automatically after completing a 10 second reading; but the settings include a continuous mode that is probably more useful.

"Instant Heart Rate" will probably need hacking to create a profile and store results because those features make use of Google services. The food/recipes section is squashed on the square display. I think the workout section needs a profile. There are banner adverts for premium services (££/year) and the close button opens them! When the adds open, there is a prompt saying "Instant Heart Rate" has stopped working: Wait or Close (its actually running fine - select Wait, then exit the advert).

So this works with caveats, and might not be what you are looking for?

Not many people here are going to have a Kardia peripheral, and not many will have enough time to hack apps, but please do let us know what you need..