We knew it was important to test our app widely to create something that served public health needs, worked technically and was easy to use. That's why we carried out rigorous testing – with the first Isle of Wight trial in May and June 2020, as well as a series of field tests.

That testing revealed that contact reliability of our original app was not sufficient. Users would be unlikely to trust the app. Therefore, it would not be effective in helping manage the spread of coronavirus (COVID-19).

The government decided that the Google and Apple approach had the highest likelihood of achieving its goals. On 18 June, the government announced we'd started the next phase of development in building an app that supports the end-to-end NHS Test and Trace service. This uses the Google and Apple decentralised exposure notification framework. 

This will bring together the functionality required to carry out contact tracing, but also makes it easy to order tests, and get advice and guidance to help people self-isolate. This will support our vision of helping more people get back to the most normal life possible at the lowest risk.