> Every time your phone sees another phone, they get one of your tickets and you get one of theirs. This is exactly how the German app works. It broadcasts ano

> Every time your phone sees another phone, they get one of your tickets and you get one of theirs. This is exactly how the German app works. It broadcasts anonymous Bluetooth beacons, and logs whatever beacons it saw. If you are infected, your app sends to the server "I saw these beacons then found out I'm infected", and the server updates its live infection list. The one in Play Store uses Google Exposure Notification Framework of course, but a de-Googled version is on F-Droid: https://f-droid.org/packages/de.corona.tracing/ https://f-droid.org/packages/de.corona.tracing/