The announcement came in the latest release of updates to the companies' software intended for public health agencies to use for coronavirus contact-tracing apps, which will notify people who may have been in contact with infected individuals using Bluetooth technology.
The one-country limit will "promote high user adoption and avoid fragmentation," the companies said in a press release.
Apple and Google also released the first images of the anticipated apps Monday to show how user consent will work with the technology.
"Apple and Google are continuing to work in support of [public health agencies] by providing the technical foundations on which PHAs can build apps for exposure notification. ...Since Google and Apple will not be building the apps, these updates are a part of the companies’ continued efforts to support developers building these apps on behalf of the health authorities," the companies said in a press release.
The tech giants are also providing health agencies with user interfaces, sample code for iOS and Android devices and a list of policies that developers must "follow to distribute apps in the App Store and Google Play” using the Apple-Google software," according to the release.
Health agencies can begin the process of developing their respective apps, the companies told reporters in a Monday phone call.
Policies for health agencies include mandatory user consent to use the app, mandatory user consent to share positive results with health agencies, an agreement to collect only the minimum amount of data necessary to response efforts and an agreement to not seek location data.
Perhaps most significantly, the companies have limited use of their software to only one contact-tracing app per country in their policy updates, which means the United States can only have one contact-tracing app that uses the Google-Apple technology unless government officials opt for a statewide or regional approach.
Google and Apple told reporters that different countries will likely take different approaches to contact-tracing apps, and limiting the technology to one app per country will keep the companies' approach flexible for other countries.
An Apple spokesperson told FOX Business that if the United States takes a state or local approach, different app developers representing different states will be allowed to use the Apple-Google software.
The tech giants have been moving quickly to release short-term efforts with the contact-tracing software as they continue to work on getting the software to health agency app developers in a more long-term solution, the companies told reporters in a Monday press call.
Apple and Google also made sure to double-down on the point of privacy, saying the software doesn't use location data, uses random Bluetooth codes to notify phones that have been in contact with other phones and requires user consent. Users can share COVID-19 test results with health agencies using randomized ID keys so they can notify others who may have been in contact with those who have the virus.
App developers who have created other official COVID-19 apps in several different states told Reuters that using GPS location data would be vital to creating a contact-tracing app, contrary to Apple and Google's policies that say the software would not use location data.
Such a policy will require PHAs to use more unstable workarounds to track phone locations, the developers told Reuters.
Apple and Google will continue to release updates on the software throughout the month, and health agencies are expected to start launching their apps this month.
Last week, the tech giants released the first components of their software to a select group of global app developers for an opportunity to test the software and provide feedback to Apple and Google before it is officially released in May.