Genuine question, but considering that @Google has data of its user's locations,down to the steps, why not build a #COVIDー19 trace/tracker?

Add an additional button, allowing users to select if they're tested positive for COVID, get their previous locations in the past 2 weeks-

- and map it out onto a new map view, then use same data from other users & see where its most likely to be contagious

From the data itself, you'd derive possible contagious locations & probability of getting infected from location X -