The Covid tracking apps aren't reliable enough to trust anyway, with both false positive and false negative interactions. For example, you could walk past someone with a recent positive test with a wall separating you, but still get a positive hit making you think you were at risk. If a person is unknowingly infected that you do some in direct contact with, no hit on the tracker. If someone coughs or a surface you later touch after they have left, again, no hit even though you are at high risk.
I would say don't bother with them and just practice whatever safeguards you feel necessary as you go about your day.