Apple and Google partner on COVID-19 contact tracing technology - Apple
Apple and Google announce a joint effort to help governments and health agencies reduce the spread of the virus, with user privacy central to the design.
Google and Apple Coronavirus Tracing
COVID-19 apps - Wikipedia
Coronavirus: Apple and Google team up to contact trace Covid-19
About technical updates to NHS Covid-19 app
Digital contact tracing and privacy
UK collaborates with Google, Apple on contact tracing App
Apple, Google will build coronavirus contact tracing software right into your phone
EXPLAINER: How phones can alert you to COVID-19 exposure
Bidirectional contact tracing could dramatically improve COVID-19 control
Apple and Google COVID-19 contact tracing apps not widespread yet
Smartphone apps in the COVID-19 pandemic