"Portana" is Cortana ported over to Android
Portana also doesn't connect to Microsoft's servers and only speaks Italian. Apparently, the hacker group was able to get to Cortana's backend without Microsoft's approval.
Last month, a report from Reuters said that Microsoft was planning on making Cortana available to iOS and Android users as a stand-alone app, but Microsoft has not officially confirmed this speculation. Marcus Ash, the group project manager for Cortana on Windows Phone, said last summer that Microsoft would be interested in sharing Cortana with other platforms.
source: VentureBeat via WindowsCentral