On Wednesday, Google and Apple launched their digital contact tracing technology that could help track COVID-19, the disease caused by the new coronavirus.

In April, the two tech giants announced they were teaming up to build Bluetooth-based technology in order to fight against the pandemic.

The companies’ exposure notification application programming interface (API) will be available to local and state public health agencies and governments to develop apps that will help notify people through smartphones if they meet someone with COVID-19.

That API is available through a new software update in the iOS and Android operating systems that Apple and Google pushed out Wednesday.

The companies said in a joint statement, “Over the last several weeks, our two companies have worked together, reaching out to public health officials, scientists, privacy groups and government leaders all over the world to get their input and guidance.”

They explained that the technology they have developed is not an app. “Rather public health agencies will incorporate the API into their own apps that people install. Our technology is designed to make these apps work better,” they added.

Apple and Google said if a person is diagnosed with COVID-19, it is up to them whether to report that in the public health app. “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,” they said.

CEO of Apple Tim Cook said, “Technology can help health officials rapidly tell someone they may have been exposed to COVID-19. Today the Exposure Notification API we created with @Google is available to help public health agencies make their COVID-19 apps effective while protecting user privacy.”

Apple and Google said some American states and 22 nations would be using the software. However, the companies did not provide a list of all the government agencies using it, according to The Washington Post.

In April when the collaboration was announced by Apple and Google, Jennifer Granick, American Civil Liberties Union surveillance and cybersecurity counsel, said people would only trust such systems “if they protect privacy, remain voluntary, and store data on an individual’s device, not a centralized repository.”

“At the same time, we must be realistic that such contact tracing methods are likely to exclude many vulnerable members of society who lack access to technology and are already being disproportionately impacted by the pandemic,” she added.

“To their credit, Apple and Google have announced an approach that appears to mitigate the worst privacy and centralization risks, but there is still room for improvement,” Granick continued. The article originally appeared on Fierce Healthcare.