CA Notify, exposure warning app, goes live across California

A program to let people in California know about their exposure to COVID-19 is now available statewide.

The app, called CA Notify, is available on smartphones. 

Android users can download it through the app store while iPhone users can activate the built-in feature. It’s accessible by enabling “exposure notifications” in the settings area of an iPhone.

The voluntary program notifies users who have been in close contact for 15 minutes with another user who has opted into the system and tested positive for the coronavirus.

The identities of users are concealed by BlueTooth technology that generates random numbers called keys that change every few minutes. Users’ phones exchange keys and will transmit a message when one user has been near a person who’s been infected. 

The app has already been in use among 300,000 people across seven campuses in the University of California system.

At UC-San Diego, 10,000 students, faculty and others signed up for the pilot program.

Interactions among that group triggered roughly 50 notifications of possible exposures via the app. Students told authorities they modified their behavior because of the app, suggesting it could be a useful tool in curtailing the virus’s spread.

California is the 20th state in the country that has launched the program.

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