Those interested in kicking Cortana's tires can sign up for the test and install the app from the Google Play Store. Users will be able to search Bing with their voice, set reminders and send text messages. The app will sync with preferences users have set up on any Windows 10 devices, so they get access to information like news stories personalized to their interests, along with reminders and flight information.
However, the Android version doesn't yet have all the features currently in the Windows version, such as opening apps and responding to "Hey Cortana." It's not clear whether those capabilities will ever come to the Android app. In addition, the app is only available to people in the U.S., though Microsoft says it plans to roll it out to other markets at an unspecified date.
It's part of Microsoft's overall strategy of porting its services to multiple platforms, even those it doesn't own. In this case, Microsoft is making Cortana portable and thus more convenient for people who use it on Windows PCs and tablets but whose smartphone runs Android.
Because the Cortana app uses Bing, its availability on Android could help Microsoft gain search share against Google.
Microsoft plans to release a version of Cortana for iPhone users later this year, though it's likely that the Apple app will be hobbled compared to its Android and Windows counterparts. Apple doesn't allow third-party apps to do things like replace Siri's functionality when users press and hold their device's home button, a feature that is available to Cortana on Android.