The UK is having another go at testing a track and trace app after several false starts. And it has chosen one of the hardest-hit places in Britain during the first coronavirus wave to do so. 

As life returns to some semblance of normality in the London borough of Newham, the British government wants to try and keep it that way. So from Saturday, residents can start downloading a track and trace app for the coronavirus. 

It's the latest trial of a technology that everyone hopes could save lives. Most of the region's residents received a letter in the post this week, complete with barcode and installation instructions. 

One employee of a high street chemist in the area said she found it clear but that elder relatives, most vulnerable to infection, had struggled to operate it. Another, who had two children in hand, told us she hoped it would make this nervous community feel safer if it worked – because a previous trial of a since-abandoned version of the app on the Isle of Wight in southern England came and went. 

Even at the end of June, opposition parties were asking why prime minister Boris Johnson's government hadn't done what at least some other countries had and set up a successful app.

Nearly three months later, it has still not emerged. And now the agency overseeing the process, Public Health England, has been disbanded and replaced with a new one, the National Institute for Health Protection, responsible for dealing with pandemics, including test and trace.

In the meantime, mass testing is being stepped up, as announced last week by health secretary Matt Hancock. "We're going to expand it, essentially by almost 10 times," said Hancock, "so that we get more detailed information about where the virus is taking root."

More quarantine measures kicked in on Saturday for those returning to the UK from Croatia, Trinidad and Tobago, and Austria as well, leading to a rush home before the deadline. Tourist and travel industry executives alike have expressed frustration at the continued unpredictability of such sudden announcements. But the government is unrepentant.

Households have been banned from meeting again in three towns, including Oldham in the north of England. A full lockdown has been avoided, though. "There's a degree of relief," said Sean Fielding, leader of Oldham council. "We made a strong case in the last 72 hours about why that would be the wrong solution for the problems we are facing in Oldham."

Experts agree, though, that track and trace is still absolutely vital. A successful trial in the place hit hardest first time round may help ease some of the anger felt here in Newham. Another false start may exacerbate it.

Video editor: David Bamford