Wait is over Cortana Virtual Assistance has arrived android.Developer from XDA leaked the beta apk file of Cortana from Microsoft.
Here am giving you download link of Cortana apk file at end of the post.Cortana for android official announced in last 4 month that they would be releasing Cortana  for android too.Huge demand and craze of Cortana made Microsoft developers to force them self to release Cortana for android.
Official Cortana For Android will take more a month of time. Due to high accuracy and speed Cortana gives answer are amazing compared to Google Now.
Download:  Cortana For Android Apk