Features of the app include contract tracing using Bluetooth, risk alerts based on people’s postcode or district, QR check-in at venues, Covid-19 test bookings and symptom checkers.

The system generates a random ID for an individual’s device, which can then be exchanged between devices via Bluetooth. Certain businesses in England will be legally required to display NHS QR codes so customers with the app can use them to check-in.

The government said the app does not hold personal information, and only requires the first half of people’s postcode with no personal data shared with the government or the NHS.

Any in-app activity will not come out of the data allowances for Vodafone, Three, EE and O2, Sky and Virgin customers.

The latest version of the app has been trialled in the London borough of Newham and on the Isle of Wight over the past month, but attempts to build a contact tracing app for Covid-19 have been dogged with controversy after a previous ‘centralised’ contact tracing app was dropped by the government.

The centralised version of the app used Bluetooth signal technology, and sent data on who may potentially have Covid-19 to a central computer server. It was abandoned earlier this year after a trial on the Isle of Wight.

The new version of the app is based on a ‘decentralised’ approach and uses technology designed by Apple and Google.

Scientists within the Alan Turing Institute and Oxford University have also worked on the app, and medical experts, privacy groups and developers of similar apps in other countries, such as Germany, have also been consulted on the app’s development.

Matt Hancock, health and social care secretary, said: “We have worked extensively with tech companies, international partners, and privacy and medical experts – and learned from the trials – to develop an app that is secure, simple to use and will help keep our country safe.

“Today’s launch marks an important step forward in our fight against this invisible killer and I urge everyone who can to download and use the app to protect themselves and their loved ones.”