The application runs automatically in the background without affecting phone usage or draining the battery. The phones of Corona Flasher users send a randomly generated code to each other when they are in close contact. The phone saves anonymous contact information.
If you have been close to someone who reports illness, you will be notified of any exposure. If you have been diagnosed with a coronavirus, the health service will send you a key code. When you tap this code into the app, you anonymously notify other users of the Coron Flasher app near you of any exposure.
The app is now available on both Google Play and the App Store and can be downloaded here:
HT
Source: The Nordic Page