While US adoption of the Google-Apple Exposure Notification API has been slow, 16 nations have used it in apps; Ireland's has 1.4M downloads since early July (Sara Harrison/The Markup)

Sara Harrison / The Markup:
While US adoption of the Google-Apple Exposure Notification API has been slow, 16 nations have used it in apps; Ireland's has 1.4M downloads since early July  —  Contact tracing—monitoring who's getting COVID-19 and tracking down anyone who might have been in contact with that person so they can quarantine …