Virginia launched a smartphone app Wednesday to notify people if they have been exposed to COVID-19, making it the first U.S. state to roll out the technology. Gov. Ralph Northam (D) heralded the app as a way to catch new cases early, while stressing that it protects users’ privacy.

“This app, COVIDWISE, does not, I want to repeat that, does not track or store your personal information,” Northam said. “It does not track you at all. It doesn’t rely on GPS or your personal information, and while we want everyone to download it, it is voluntary.”

COVIDWISE, available on Google Play and the iOS App Store, uses Bluetooth signals to determine when smartphone users are in close proximity for longer than 15 minutes. If one of those smartphone users later tests positive for COVID-19, that proximity information will be used to notify people who might have been exposed to the infected individual. The app won’t tell people who they were near who tested positive, just that they were near an infected person.

“This is really another tool that we all have to protect ourselves and each other,” said Jeff Stover, who worked on the app for the Virginia Department of Health.

The app was made through a collaboration between Apple and Google. The two companies announced in April that they were working on a platform that could be used both on Apple and Android devices, and that would shield users’ privacy.

Northam spokeswoman Alena Yarmosky said Germany and Ireland are already using similar technology. Stover says other states are beta testing similar apps, but they have yet to launch. Stover added that Virginia’s beta testing was done “in a closed environment” with about 500 people from across the state. He estimated Virginia spent about $229,000 in CARES Act funding to launch the app.

Virginia residents who test positive for COVID-19 will now receive a six-digit PIN with their results, which they can enter into their app to begin the notification process. Contact tracers will not have access to the personal information of app users, Stover said, although tracers will tell people about the app as they conduct their work.

Skepticism around privacy during the coronavirus in Virginia is high, with some concerns leading to the spread of conspiracy theories. State Sen. Amanda Chase (R-Chesterfield), who is running for governor, wrote in a campaign ad in May, “I will not be masked, tested, tracked or chipped to support this liberal agenda.”

Publicist David Saunders of the marketing company Madison+Main says Virginia will partner with NASCAR, Virginia Commonwealth University and other companies and nonprofits to encourage people to download the app. In addition, Saunders said Virginia Health Commissioner Norman Oliver would speak about the app on conservative talk radio to underscore its protection of privacy.

“This is not a tracking application,” Saunders said. “This is where some of the other states, because of personal privacy concerns, met resistance. This is an exposure notification system.”

Northam said he would also encourage all 100,000 state employees to use the app and urged other Virginians to sign up.

COVID-19 cases continue to rise in Virginia, with roughly 1,000 new cases reported every day. A total of 2,274 people have died from the virus and nearly 100,000 people are infected, officials reported. Northam said the state’s positivity rate was at 7.2% “and that’s a good thing,” although health experts at the World Health Organization have advised reducing the figure to below 5% for 14 days before reopening.

“We can’t let up in our efforts to get the numbers down,” Northam said.

Virginia has taken several measures recently to grapple with its growing caseload. On Tuesday, it joined with six other states in a compact to jointly buy antigen tests that deliver results in 15-20 minutes.

Under the terms of the pact, Virginia will obtain 500,000 tests, although Northam did not have a date for when they would become available. Currently, Virginia is averaging between 15,000-20,000 tests a day.