This is a really interesting and problematic area. There is increasing amount of apps that claim to do health measurements with the help of "propriety algorithms" It should be noted that the writer is both a physicist AND a digital health evangelist, so I assume that he provides a balanced view that would take potential benefits of these kind of apps into account, if they had them.<p>The following excerpt is pretty damning:<p>"I practice Emergency Medicine in a Level 1 trauma center. I see what poor blood pressure management does on a daily basis. I see people arrive to my ER non-responsive, on the verge of dying, due to hemorrhagic strokes secondary to blood pressure that isn’t controlled. I frequently see hypertension become so bad that it causes flash pulmonary edema, and patients literally arrive drowning in their own lungs and unable to breath. I’ve talked to family members telling them how their loved one died because their blood pressure was too high, resulting in a catastrophic failure of their organs.<p>Blood pressure management is not for “recreational purposes”. This is not entertainment. This is real life."