Contact tracing: What's the latest on the NHS app?

Earlier this year the NHS launched a contact tracing app, which it hoped could help in the fight to control coronavirus.

The app would be able to detect if a person has come into contact with someone who has had the virus.

However the app has had to be re-launched because of problems first time round.

We caught up with David McClelland, a technology reporter, to find out a bit more about what's been going on.