Test, track, and trace has become a key message in the fight against coronavirus and on Monday we learned more about the third element to this crucial approach.
Contact tracing is seen as one of several possible remedies to help the UK out of lockdown and an app trial is now ready to go, ahead of a full roll-out across the country.
A contact tracing app is one of the Government's next big areas of focus, part of a wider contact tracing effort, as it tries to find ways to end lockdown while preventing a possible second wave of the virus.
The app uses Bluetooth to keep an anonymous log of everyone you come into close contact with. When they - or indeed yourself - present symptoms of Covid-19, tell the app and it will then alert anyone that