Your phone will tell you when you have been in close contact with someone who has tested positive for coronavirus. The alert will say:
“You need to self-isolate immediately. You have been in close contact with someone who has coronavirus (COVID-19). Tap here for more details.”
The alert will look like this:
When you need to self-isolate, this will always be visible within the app, and the app will also provide a countdown timer so that you can keep track of how long you need to self-isolate. Read more about the self-isolation countdown timer.