No clue if reported here already, just in case:
A free app is in development, which can do
Corona Tests by VOICE recognizition.
Reliability in scientific studies:
100% if infected without symptoms, 98.5% if WITH symptoms.
2020-10-29: EN
https://news.mit.edu/2020/covid-19-cough-cellphone-detection-1029
2020-12-15: DE
https://www.spektrum.de/kolumne/lobes-digitalfabrik-per-stimmerkennung-zur-corona-diagnose/1808942
It seems the usual Big Data collectors are also working since some time already to analyze various medical conditions by VOICE and AI (aside from their usual purposes)