A contact tracing app is now available in Switzerland for newer smartphones to help tackle Covid-19.

If a person tests positive for coronavirus, everyone with whom that person was in contact in previous days – within two metres and for more than 15 minutes – is alerted via the app to isolate themselves and get tested.

SwissCovid was developed by the Swiss Federal Institutes of Technology in Lausanne and Zurich. Smartphones use Bluetooth technology to communicate with each another anonymously. The system is decentralised with contacts and data stored on devices rather than on an external server. It is the first in the world to use the OS updates from Apple and Google.

But people with older phones won't be able to access the app. You need an iPhone 6s or a more recent model, or an Android 6. The larger mobile phone providers Swisscom, Salt and Sunrise say approximately every fifth smartphone will be excluded.

There’s no exchange with tracing apps from other countries although this is technically feasible.