In early March, Microsoft revealed their plans to bring Windows 10's companion application Cortana to iOS and Android phones as a standalone app, in addition to Windows phones. Cortana could not be limited to Windows phones, as Apple limited Siri; there is too much room for competition for them to do that and too many Windows users.
The standalone application on Android and iOS will be almost as unlimited at the one woven into Windows versions, but will feature some differences. These differences come from the lack of "Hey Cortana" being a function, no ability to open apps with voice commands and toggling settings. These features won't be available at launch, but may be added later on.
Cortana will be available on Android at the end of June and later on the iOS.
