Is the idea already tested, in testing? or is it batshit crazy (⌐■_■)?
If you try hard enough I would guess you can get statistically significant data out of it in areas where a significant portion of the public is infected, but it’s a huge step from there to diagnostically significant data, with both few enough false positives and few enough false negatives.
Telemonitoring symptomatic coronavirus patients requires thermometer and pulse oximeter.
https://www.healthleadersmedia.com/clinical-care/how-health-...
https://www.cnbc.com/2020/03/13/hospitals-using-digital-tool...
> Patients who are identified as likely positive for COVID-19 in an emergency department but are not admitted are being sent home with a thermometer and pulse oximeter to monitor their symptoms at home under the supervision of the health system's telehealth team.
When temperature raises and blood oxygenation drops you should be rushed to ICU to save your life.
I am sure one can make fancy iOS app for that.