Is a successful contact tracing app possible?

Is a successful contact tracing app possible? These countries think so: If contact tracing apps are following Gartner’s famous hype cycle, it’s hard to avoid the conclusion they are now firmly in the “trough of disillusionment.” Initial excitement that they could be a crucial part of the arsenal against covid-19 has given way to fears it could all come to nothing, despite large investments of money and time. Country after country has seen low take-up, and in the case of Norway and the UK, apps were even abandoned.

So what advice do these countries have for others?
1. Remember every case matters
2. Manage expectations
3. Work in the open (or you won’t gain public trust)
4. Set the right parameters
5. Give it time