While the “Hey Cortana” prompt still isn’t available in the beta version of the app on Android, Microsoft Cortana can be your main digital assistant on Android now. You now have the ability to replace the Google Now shortcut, which has you pressing and holding down the home button, with Cortana. We’re not sure yet if they “Hey Cortana” prompt will be making its way too Android, possibly because of hardware limitations, but we’ll take what we can get now. If you’re interested in being a beta tester for Cortana on Android, you can check the sign-up process here.
Source: The Verge