The Times (sorry no share token) has some interesting articles on covid apps in different countries.
In short, some countries are doing better than others... but
No one has a really significant take up of the app. Germany is at the higher end at 10million downloads vs 80 million pop. France are at 1.5million.
And nowhere is the app having any meaningful impact on alerting people to quarantine or get tested.
The headline figure is that in France just 14 people have been told via the app that they have been in contact with someone whose tested positive. But even in Germany the figure in in the low hundreds.
Nowhere has got over the issues flagged by the Uk govt that the distance measuring isn't really very reliable either.
Fair to say that we are far behind the curve. But also fair to say that nowhere is an app moving the dial on the virus.