Although 55,000 downloads have been achieved since it launched on the Isle of Wight last week, some residents have been unable to make the app work.
Dr Geraint Lewis, NHS England’s chief data officer, told journalists on Sunday the NHS is urgently trying to make it available to those phones which cannot support the app.
Dr Lewis said: “There are three elements to it — we had to start with some of the most common phones first and we are working our way through the list.
“Secondly, if the physical phone itself is very old, it might not have the low energy Bluetooth function within it [to make the app work] and there is nothing we can do about that.
“The third reason is the operating system might be old. The app supports systems 8 and above for Androids and iOS 11 and above. If is it the operating system that is a problem, we can advise people to update their phones.”
“Like any high-quality app, the intention is for it to improve over time.
“For example, things like Facebook continue to update overnight and it is continually learning and improving and that is what we are proposing to do here.
“And that is what Islanders are able to help us with.
“For example they might find the way we phrase something is a bit confusing so we can change the wording and make it a bit simpler to understand its purpose.”
There still remains queries over how the app works and whether data will really be kept private.
Dr Lewis said: “The way the app works, the user data is completely anonymous up until the point where you want to order a test kit, at which point you have to give us the contact details so we know where to send the test.
“All of the legal protections people would expect, such as GDPR, all of those things apply as well as the same protections we have in place for any NHS data set.
“The NHS looks after people’s very private details and we have established ways of dealing with that.”
When the coronavirus pandemic is over, the app will be removed from the app stores and people asked to delete it from their phones.
“It may be better to think about ‘mothballing’ it,” said Dr Lewis, “just in case another pandemic were to come back in the future.
“Then we can hit the ground running because we will have all of the intellectual property available in the NHS app.”
Simon Bryant, director of public health for the Isle of Wight, said there will be a lot of learning from it that might be helpful.