Google and Apple have released their contact-tracing software which can be used by smartphones across the globe.

In a joint statement, the tech giants announced they have launched its Exposure Notification API, which can be used by public health agencies to build contact-tracing apps.

From May 20 the technology was made available to all interested public health agencies.

The statement added: “What we’ve built is not an app—rather public health agencies will incorporate the API into their own apps that people install.

“Our technology is designed to make these apps work better. Each user gets to decide whether or not to opt-in to exposure notifications; the system does not collect or use location from the device; and if a person is diagnosed with Covid-19, it is up to them whether or not to report that in the public health app.

“User adoption is key to success and we believe that these strong privacy protections are also the best way to encourage use of these apps.”

Apple and Google announced in April 2020 that they were teaming up to create technology which will enable the use of Bluetooth to help governments and health authorities track the spread of the virus.

The NHS is currently piloting its own contact-tracing app on the Isle of Wight. Health secretary Matt Hancock has previously said the app would be rolled out by mid-May, as had NHSX chief Matthew Gould when grilled for a data by parliament’s science and technology committee.

But recent reports have suggested the launch date has been pushed back to June 1.

The NHS has chosen to develop a centralised system, meaning data collected from the app is sent to a centralised database rather than between devices.

This differs from Apple and Google’s decentralised approach, which collects data on contacts and shares between devices. This approach is widely favoured by privacy and technology experts.

However NHSX is reportedly working on a second contact-tracing app using Apple and Google’s technology to mitigate these concerns.