Is there a link to it? Or anything I can search for in the App Store?
Not that I have. The only people who have been sent the link are the Isle of Wight residents who are trialling the app. The BBC says “while in theory there is nothing to prevent the details being shared and used by others elsewhere, NHSX hopes this will not happen as it could confuse the feedback it receives” - https://www.bbc.co.uk/news/technology-52532435 .