Microsoft for some time preparing and Android version of Cortana, and now the beta version leaked to the public. Download and try.
Cortana's Siri and Microsoft debuted Windows Phone devices, as Windows 10 upgrade expands all other Microsoft devices. Cortana to be offering the same capabilities and features - communication and management of the voice commands.
beta version of Cortana Android, accidentally or intentionally leaked in the form apk package and is available to download from the link below and easy to install and try out on your Android. Keep in mind that this is a draft and it might not all work properly. What definitely does not work is the ability to start Cortana voice command "Hey Cortana," but everything else more or less in order, and you will need to log in to their Microsoft account.