Is this something you’ll be turning on?

Apple has begun letting its iPhones carry out contact-tracing without the need for users to download an official Covid-19 app.

As an alternative, owners are being invited to opt in to a scheme called Exposure Notifications Express (ENE).

This keeps a 14-day log of other phones detected via Bluetooth and serves an alert if one or more of their users is later diagnosed to have the virus.

The local public health authority will determine what the notification says.

It might tell the user to download a more fully functional app for further guidance.

However, it also gives officials the option of not developing an app of their own, in which case the user could be directed to go to a testing centre or to call a hotline for more information.

IPhone owners who become ill without having received a warning message can still cause a cascade of alerts to be sent to others. But since they will not have an app to start the process, this will be done by tapping on a text message sent by the public health authority to their smartphone after a positive diagnosis.

The facility is being rolled out as part of the latest update to Apple’s mobile operating system, iOS 13.7, which has just been released.