Microsoft has pushed out a new update to its Cortana for Android app, bumping it to version 1.8.0.1066. The update - aside from some improvements and optimizations - brings back the Hey Cortana feature. If you recall, the Hey Cortana feature - which lets users invoke the Cortana personal assistant through voice activation - was removed from the app in December last year following reports that it interferes with Google Now's 'Ok Google' functionality. Aside from bringing back Hey Cortana, the update also makes it easier to access to the voice button, and includes some battery-related...
Source: http://www.gsmarena.com/cortanas_android_app_regains_hey_cortana_feature-news-18692.php