https://www.theguardian.com/technology/2020/apr/28/nhs-coronavirus-contact-tracing-app-ready-for-use-in-three-weeks-mps-told

Deployment of coronavirus tracking system to be trialled in ‘small area’ before roll out

An NHS app that alerts users to recent contacts who are infected with coronavirus will be ready for deployment within three weeks, according to the chief executive of NHSX, the digital arm of the health service.