Google recently made a version of the Nexus 5’s Google Now launcher available to all Nexus and Google Play Edition devices.
The Google Now launcher, which debuted as part of the Nexus 5’s user interface, includes Google Now as part of the home screen. Google Now was upgrade from a widget to one of the home screen panels. The launcher lets people trigger voice search or voice commands by saying “OK Google” when on their home screen. Further, with a full home screen panel, Google Now has more room to reveal info cards, which provide information about travel plans, scheduling, the weather, real-time traffic, and more.
The Google Now launcher is free to download from the Google Play Store, but requires Android 4.4 KitKat and either Nexus or Play Edition devices.