OLYMPIA, Wash. (AP) — A COVID-tracing smartphone app that prompted concerns about the spread of misinformation and privacy went into effect yesterday in Washington.

Governor Jay Inslee told a news conference that University of Washington developers created the app along with Apple and Google.

The app called WA Notify then directs the user to a website with next steps to take and a list of testing sites.

It’s completely voluntary to use and is already loaded onto iPhones and available to download for Android phones.

Social media posts earlier in the pandemic had caused worry among some iPhone users with false claims that the app was tracing them.