@DavidR,
That's why I fear that a covid-19 app is never gonna work. It is just gonna give us all a false sense of being secure.
(yep, for what actually?). Any sneeze or cough could be "that particular sneeze or cough",
especially when the elderly start to sneeze and cough.

In the old days lepers moved around with a rattle, now the alleged old corona prepper will cling to a smartphone app.
Even when they make it mandatory it does not seem to change the overall situation much i.m.h.o.
We all going to experience a plandemic crash of the economy, bigger then we have ever seen.
Better to steer away earlier than later from the situation at hand, because this seems to me to be the nastiest part.
pol