Coronavirus 4 May 2020 NHS tracing app will prove useful even if only one in five download it, project head says Sign UpGet the New Statesman\'s Morning Call email. Sign-up The NHS's coronavirus tracing app will give "really important insights" even if only one in five people download it, but if 40 per cent of people use it, it will make a "big difference" in identifying contacts of people with coronavirus, the head of the project has said. The government will launch a trial of the app, which logs distance between people's phone via Bluetooth, on the Isle of Wight tomorrow, starting with healthcare professionals, and rolling out to all island residents later this week. Matthew Gould, chief executive of NHSX, the health service's technology arm, told the human rights select committee: "What we have seen in other countries is something like 20 per cent of people downloading it. Even at that level it starts to give us a really important insight. "If we can get to higher levels – 40, 50 per cent or above – the app can really make a big difference in identifying those who have been in touch with suspected cases of Covid-19 and making sure we can identify and isolate those people earlier and faster and more effectively." He also told the committee that the app does not require anyone's personal information to operate. Bluetooth data is stored on the phone, and people are identified by a number, rather than a name. Users will be asked for the first half of their post code to help the government track virus hotspots, he said. › Why Boris Johnson should now admit his government's failures over coronavirus Image credit: MIGUEL MEDINA / Getty Images Subscribe For more great writing from our award-winning journalists subscribe for just £1 per month!