BOSTON (SHNS) – Massachusetts has become one of 29 states allowing residents with smartphones to use Bluetooth technology to learn whether they might have been exposed to someone who has tested positive for COVID-19.

With the state of emergency in Massachusetts expiring and all remaining public safety restrictions lifted, Gov. Charlie Baker on Tuesday announced the launch of MassNotify, a smartphone service developed with Apple and Google that alert users when they come in close proximity to someone diagnosed with COVID-19.

The technology, according to officials, is completely anonymous and does not share location or phone data with the state, Apple or Google.

“As we embrace our new normal, MassNotify is a voluntary, free tool to provide additional peace of mind to residents as they return to doing the things they love,” Baker said in a statement.

Users who enable exposure notifications in the settings of their phone can sign up for MassNotify, and anyone who tests positive with COVID-19 in Massachusetts will now receive instructions on how to anonymously share that test result through the program.

When two people using MassNotify are near each other, their phones will exchange randomly generated codes using Bluetooth and if someone is near another person who has shared a positive test result they will receive a notification about possible exposure to COVID-19.

MassNotify is compatible with both Apple and Android phones.