Science: how to draw conclusions from the data, how to validate the data quality is apt
In https://045.medsci.ox.ac.uk/mobile-app a group of medical researchers propose an app very similar to Fever Map. The site has lots of scientific references and info. They also published this: https://github.com/BDI-pathogens/covid-19_instant_tracing/blob/master/Policy%20forum%20-%20COVID-19%20containment%20by%20herd%20protection.pdf
The core question here is how to make valid "guestimates" from the collected data. If we have X cases of fever, Z cases not having fever, and the responders gender and age distribution is known, how do we interpolate that into a value of how many are likely to have fever in the whole population?
We need to be able to answer to the question "How many people are likely to be infected in area X?"