The app uses technology developed by Google and Apple who are engaged in a joint effort to enable the use of Bluetooth technology to help governments and health agencies around the world reduce the spread of the virus, with user privacy and security central to the design.
Apple and Google have published details of this technology
This new technology is only available in the newest versions of the iOS and Android operating systems. For some users this will be a problem because the new operating systems are not supported on older iPhone models (iPhone 6 and earlier).
