In one of the most far-ranging attempts to halt the spread of coronavirus, Apple and Google said they were building software into smartphones that would tell people if they were recently in contact with someone who was infected with it.
The technology giants said they were teaming up to release the tool within several months, building it into the operating systems of the billions of iPhones and Android devices around the world. That would enable the smartphones to constantly log other devices they come near, enabling what is known as “contact tracing” of the disease. People would opt in to