Android: When the Nexus 5 first came out, there were whispers that the new launcher would arrive on all devices. While you could sideload it yourself, there wasn't a simple option to download it from Google and get updates. Until now.
Today, Google officially released the Google Now Launcher to the Play Store. This launchers has new, bigger icons, a Google Now screen directly to the left of your home screen, and a cleaner app drawer. You can also say "Ok, Google" while on the home screen to trigger voice commands.
Unfortunately, the app only seems to be available for a limited number of devices at the start. If you have a recent Nexus or Google Play Edition device, you're in, but everyone else has to wait. Still, that's a few more devices than were officially supported before and it's likely only a matter of time before more devices get on the list.
Google Now Launcher | Google Play Store via Android Police