California boasts the highest contact-tracing app activation rate of any state in the country, with more than 8 million users, officials said.

Nevada, Maryland, Virginia and D.C. will be the first to use a version of the tech giants' jointly developed API that does not require the installation of an app.

The state is the latest to publish a smartphone app based on the tech giants' joint programming kit in an attempt to track the spread of COVID-19.

The Covidwise app, which runs on the tech giants' Bluetooth-based API, is being made available to all Virginia residents, Gov. Ralph Northam said.

The app will be targeted at students returning to the state's college campuses. Meanwhile Google says as many as 20 states are developing apps based on the API.

Some states have built contact tracing apps, but a decades-old manual process is the norm in most places as officials address widespread privacy concerns.

The state's 1,400 contact tracers will use a combination of cloud platforms, text alerts and old-fashioned phone calls to track the spread of COVID-19.

North Dakota, Alabama and South Carolina are the first states to say they'll use the tech rivals' platform to track the spread of the coronavirus.

The controversial legislation died in committee following stiff resistance from privacy advocates and even federal lawmakers.