The Apple-Google developed coronavirus contact tracing app has saved thousands of lives in England and Wales, according to the Financial Times (a subscription is required to read the read the entire article), which has this to say:
Researchers at the Alan Turing Institute and Oxford university have estimated that every 1% increase in app users can reduce coronavirus cases by as much as 2.3%.
The app has sent 1.7m notifications to its more than 21m users telling people to isolate so far. Of those, the Turing/Oxford researchers estimate that about 600,000 cases were averted by the end of December […]
Extrapolating from normal case fatality rates, that suggests thousands of deaths may have been prevented by the app.
Last year Apple and Goole released application programming interfaces [APIs] that enable interoperability between Android and iOS devices using apps from public health authorities. These official apps are available for users to download via their respective app stores. Apple and Google have also worked to enable a broader Bluetooth-based contact tracing platform by building this functionality into the underlying platforms.