NHS COVID-19: The UK’s coronavirus contacts-tracing app explained

The UK government, through NHSX, the digital arm of the NHS, have begun testing a coronavirus contact-tracing app on the Isle of Wight. The app uses Bluetooth to record proximity to others, and feeds this data into an algorithm designed to estimate possible infection risks. The app allows users to self-report symptoms, which could result in false alarms. The lack of dedicated legislation around the app and uncertainty about whether it will effectively alert about possible infections has raised questions about how effective the tool will be.