This post is also available in: heעברית (Hebrew)

The long-awaited smartphone technology to automatically notify people if they might have been exposed to the COVID-19 was released by Apple and Google. The app relies on Bluetooth wireless technology to detect when someone who downloaded the app has spent time near another app user who later tests positive for the virus.

22 countries and several U.S. states are already planning to build voluntary phone apps using this software, according to the two companies. 

Many apps rolled out by various governments around the world were not successful, encountering technical problems on Apple and Android phones. They often use GPS to track people’s location, which Apple and Google are banning from their new tool because of privacy and accuracy concerns, according to

The companies said they’re not trying to replace contact tracing, a pillar of infection control that involves trained public health workers reaching out to people who may have been exposed to an infected person. But they said their automatic “exposure notification” system can augment that process and slow the spread of COVID-19 by virus carriers who are interacting with strangers and aren’t yet showing symptoms.

The identity of app users will be protected by encryption and anonymous identifier beacons that change frequently. “User adoption is key to success and we believe that these strong privacy protections are also the best way to encourage use of these apps,” the companies said in a joint statement.

The collaboration could also contribute to other improvements. The companies said the new technology solves some of the main technical challenges that governments have had in building Bluetooth-based apps. It will make it easier for iPhones and Android phones to detect each other, work across national and regional borders and fix some of the problems that led previous apps to quickly drain a phone’s battery.