Your take on specificity is reversed. 80% specificity means that...

1. Your take on specificity is reversed. 80% specificity means that 1 in five subjects who do not have Covid-19 will be diagnosed as positive. That's annoying for the false positives who may spend a day or two taking precautions until they get their confirmation tests results and it shows clear.
2. Being in the 20% doesn't mean you have nothing, just that you don't have Covid-19. The test picked up a lung condition that sounded enough like Covid-19 to produce the diagnosis. Those who get a false positive are likely to find that they have something else worth treating, and might be glad to have learned about it.
3. The figures of 92% sensitivity and 80% specificity are not physical properties set in stone. They're a product of the area under the probability curve. If 80% is too low a specificity for a useful test then it can be increased at the expense of reduced sensitivity. For example you could opt for 90% sensitivity in order to achieve 85% specificity. But given the potential consequences of having a false negative roaming around in the community without taking precautions, it makes sense to have a high sensitivity at a reasonable cost in specificity.
4. The supply of tests is at least as important as the accuracy. Each RAT kit requires raw materials, an act of manufacture, packaging, logistics and shelf space. The most accurate test in the world is useless of you can't get it. With the mobile app you have no supply issues regardless of how many people are using it.
5. The cost per test is also at least as important as the accuracy. At $15 each how many tests can a family afford for each child two to three times a week, plus additional tests for adults as and when required. How many families have $100 per week free in their budget for RATs? Because Resapp's cost base is very low and doesn't increase with usage they could roll out a mass market test at low rates and still be profitable. Per use prices could be as low as 50c, or on a $25 monthly unlimited use subscription and Resapp would be raking in the cash.

In any case, it's really hard to take your comments seriously when your research is so superficial that you issue such staggeringly ignorant statements like "How is the app going to work for the very many (in some age brackets, the majority) who are asymptomatic and have no cough?"