Google launched the Nexus 5 late last year with an interesting new home screen interface. At the time it said the updated launcher was only for the Nexus 5, but it was easy to trigger the new launcher on other devices by copying the launcher app from the Nexus 5. Now officially dubbed the Google Now Launcher, it has been released to the Play Store for a few more devices.
The Google Now Launcher app is actually just a stub APK. It directs the system to the Google Search app, which is actually drawing the home screen. The code to do this already exists on virtually every Android phone and tablet thanks to the app updates in recent months.
This means Google can improve its home screen launcher through the Play Store independent of OS updates.
While installing the launcher stub will add the Google Now Launcher to almost all phones, Google has only made it officially available for Nexus and Google Play Experience devices right now. If you install it, simply set the Google Now Launcher as your default home screen.
It supports transparent system bars on Android 4.4 devices and creates a new home screen panel on the far left that becomes the new Google Now interface. The "Ok Google" trigger phrase can also be used to launch voice search from the home screen.
Users can also add as many home screen panels as they like just by dropping a widget or icon on a new page on the far right. The Google Now Launcher automatically removes empty panels. The new launcher should offer to import the layout from your previous one when it starts up.
The Google Now Launcher is free, but there's no word when it's going to come to more devices. Aside from the officially supported devices and sideloading option, some phones running KitKat-based ROMs should show up as compatible.
For more, see our comparison of the Samsung Galaxy S5 vs the Nexus 5, straight out of MWC 2014.