MOUNTAIN VIEW, CALIFORNIA—Today Google is releasing the third developer preview of Android N , the new version of Google's mobile operating system due this fall. Developer Preview 3 continues to tweak existing features while adding new ones, and stability should also be improved; Google tells us that it considers this build to be "beta" quality, ready for developers and more-ambitious users to use it as their daily driver.

One of the largest additions is something we found evidence of in the second preview build: a new Google-developed VR service that will make it easier to turn compatible Android smartphones into modest VR headsets like Samsung's Gear VR. We have more on the feature and its system requirements in a separate article.

Also new to DP3 is a revised partitioning scheme that borrows from ChromeOS in order to expedite the installation of system updates. Android N is already using a combination of just-in-time (JIT) and ahead-of-time (AOT) code compilation to get rid of the lengthy "app optimization" part of system updates. DP3 reduces the amount of time your phone actually shuts down to install updates to the system partition. Theoretically, Android updates should now work more like ChromeOS updates: install them in the background and then do a quick reboot to make the update take effect.

The new preview is available for the Nexus 6, 9, 5X, 6P, and Player; the Pixel C tablet; the Sony Xperia Z3; and the General Mobile 4G Android One phone. This isn't necessarily the full list of Nexus and "stock" Android devices that will get the final update, but Google still won't say whether it plans to support older devices currently on Marshmallow like the Nexus 5 or 2013 Nexus 7. Google plans to release two more preview builds in the coming months ahead of a third, final release in the fall. Among its other major features are a split-screen multitasking mode for tablets, the Vulkan graphics API, better notifications, new emoji, and several new UI customization options.