1. Using end of fingertip (rather than whole fingerprint surface) gives same reading as my smartwatch - and is worth the $2.99 for lifetime access, especially if you have not got access to a smartwatch, or want reassurance from a second measuring device.Good app functionality and easy to use.
2. Not sure about the SpO2, though it seems correct, I had read margin of error is +/- 4% using the phone apps.If you want a Pulse Oximeter for real actual use (not just somewhere to record SPO² readings) then this is the only app that I would recommend.
3. Of course you have to sit still (like with any of these apps).If your device supports it (Samsung Note 4 through 9 and Galaxy S6 through S10 according to the developer), this app is an improvement over Samsung Health's pulse ox module - it provides a history, which can be exported (a premium feature, but not expensive).
4. Easy to use pretty intuitive works great with my Samsung S8 (review updated with correct phone type.
5. The Samsung Health app got rid of the oxygen saturation and I am post-op so wanted to keep track of things even if I appreciate that it's not quite the same as in the hospital but so far so good.
6. But has a horrendous ad implementation to the point that ever time I measure and every individual measurement I review plays an ad, and un-mutes itself each time.
7. Great user interface: easy to use, good graphics, good data logging.
8. It works with either the Samsung built-in heart rate sensor or the flash/camera.
9. Plus it's quick to use and can be calibrated to some extent (though I haven't done this myself).So far so good.
10. The only other issue would be, I have an advanced case of A-fib and it seems like it can't pick up a signal to get started.
11. It usually starts fine begins to show blood gas etc and then says it is searching and then it tells me to try again.