Heard about and installed what I found to be an intriguing health app called Together by Renee. Available in US iOS app store.
Has a feature called Vitals. You aim selfie camera at face for 60 seconds and it provides vital readouts including pulse rate, breathing rate, blood ox level and blood pressure. Now I generally have normal blood pressure, and low pulse rate. It gets both pretty close compared to wrist cuff BP and Apple Watch PR readings, but still can’t compare blood pressure to something high. Really surprised this can all be done using smartphone camera.
Much easier to use then BP cuff and finger based readings.
Can’t find any info on this tech.
And so far it is free. Seems like this could be pretty big if readings prove to be fairly accurate.