COVID-19 has brought together two unlikely rivals. Apple and Google announced Friday they are teaming up to build software in smartphones that alerts people who recently came into contact with someone with the virus.

They plan to release the technology next month. It will use Bluetooth on phones to allow users who opt-in to tap into an app from health authorities. 

Contact tracing, according to health officials, has become a valuable tool to help contain the spread of the virus. Several companies, including OnAudience.com, along with health authorities, universities, and non-profit groups have been working to develop opt-in contact tracing technology.

OnAudience.com, a part of Cloud Technologies Group, for example, developed an app called COVID-19 Prevention Tool. OnAudience CEO Maciek Sawa believes it will become commonplace for mobile devices such as smartphones to warn people about the risk of becoming infected. 

Apple and Google will include an application programming interfaces (APIs) and operating system-level technology to assist in enabling contact tracing. The plan is to implement this solution in two steps while maintaining protections around user privacy. 

In May the companies will release APIs that enable interoperability between Android and iOS devices using apps from public health authorities. These official apps will be available for users to download via their respective app stores. 

The two companies also will work to build in Bluetooth-based contact tracing into the underlying platforms. It will allow more individuals to participate if an individual chooses to opt in, as well as enable interaction with a broader ecosystem of apps and government health authorities.