Health Secretary Matt Hancock has called on people across the South West to download the new NHS Covid-19 app, which has now launched across England and Wales following rigorous testing and successful trials.

The NHS Covid-19 app will alert users if they have been close to someone who later tests positive for coronavirus, as well as providing risk alerts based on a user’s postcode. It allows users to scan QR codes to check in at venues on the app, (businesses are now required by law to display the QR posters) and also allows people to book tests, if they have symptoms.

The app works by logging the amount of time you spend near other app users, and the distance between you, so it can alert you if someone you have been close to later tests positive for Covid-19 – even if you don’t know each other.

The app will advise you to self-isolate if you have been in close contact with a confirmed case.

The UK’s major mobile network operators, including Vodafone, Three, EE and O2, Sky and Virgin, have confirmed that all in-app activity will not come out of customers’ data allowance.

The Health Secretary said: “We are at a tipping point in our efforts to control the spread of this virus.

“With infection rates rising, we must use every tool at our disposal to prevent transmission, including the latest technology.

“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 and 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.”

The British Medical Association (BMA) says that while the app should enable more cases to be identified, it must work in tandem with a “properly functioning test and trace system”.

BMA Council chairman Dr Chaand Nagpaul said: “Tracing and isolating people who have been in contact with infected individuals is important in helping prevent spread of the virus. The more people who download the app, the more people who may have Covid but otherwise wouldn’t be traced should be identified and instructed to isolate.

“The use of the app does not diminish the pressing need to have sufficient testing capacity, and must complement a properly functioning national test and trace system which can also quickly identify local outbreaks.

“The overall priority for the Government must be to drive down the infection rate via stringent public health and infection control measures. This includes minimising mixing of households indoors, rigid physical distancing of two metres rather than a confusing 1 metre ‘plus’, and consistent use of face masks in all settings where distancing is not possible.

“It is also crucial, even without a test, that anyone (or a member of a household) who develops symptoms must self-isolate. 

“Only by employing all of these measures can we hope to minimise the spread of this deadly virus.”