I disagree with the failure claims except for lack of adoption. How can unreliable distance measurements be an issue? Actual viral spread over distance is a mu

I disagree with the failure claims except for lack of adoption. How can unreliable distance measurements be an issue? Actual viral spread over distance is a much, much bigger uncertainty. Even improving distance measurements to the nanometer wouldn't make much of a difference considering transmission prediction. Sometimes the virus bridges tens of meters, other times it fails to make landfall in a prolonged skin on skin situation. Measuring impact is a simple polling research problem: if you want to know this kind of thing (and I think you should) you need to accompany your PCR tests with a tiny little questionnaire collecting data about why the test was done. Failure to collect that data is entirely unrelated to the app.