GENEVA: Switzerland's Covid-19 contact-tracing app will roll out to the public on Thursday, the government said, urging everyone to download it on their smartphones.

The free SwissCovid application uses Bluetooth wireless technology to register other phones that come within two metres for around 15 minutes or so.

It then alerts people who may unwittingly have been in prolonged proximity with someone who later tested positive for the novel coronavirus.

"We want to stem the uncontrolled spread of the new coronavirus," the government said Wednesday in a statement.

"The more people use the app, the better we can achieve this goal."

The app is optional and no personal data or location information is used.

Anyone who tests positive for the virus is given a code by the regional health services to enter into the app.