The exposure notification app uses Bluetooth to swap codes between mobile devices. If someone tests positive for COVID-19 and they mark that status on Immuni, it will alert people who have been in close proximity with that person. They’ll be advised to self-isolate and get tested for the virus themselves to limit the spread of COVID-19. 

Concerns have been raised that the app will violate people’s privacy. However, the Italian government says the app doesn’t collect personal or geolocation data. Data stored on smartphones is encrypted, as are connections between the app and the server. All app-related data, whether on people’s own devices or servers, must be deleted when it’s no longer needed, or by the end of the year at the latest.