Ask HN: What would an awesome contact tracing app look like?

Rigorous testing, contact tracing, and isolation is the best way to take the fight to the novel coronavirus. We can't wait for a vaccine[1].

Singapore has started something[2], but ideally the app would be built in such a way that western democracies have an appetite for it.

It'd be really great if the HN crowd who knows how to build such things would freely share their best ideas here, as this is not about who gets first to market but rather solving a critical crisis that we all face.

This includes not just front-end mobile client ideas, but also back end architecture to ensure proper security.

1. https://www.reuters.com/article/us-health-coronavirus-who-ryan/lockdowns-not-enough-to-defeat-coronavirus-whos-ryan-idUSKBN2190FM

2. https://www.gov.sg/article/help-speed-up-contact-tracing-with-tracetogether