Google has started rolling out Android O Developer Preview 4 for compatible devices. The Developer Preview 4 is a release candidate build with the latest bug fixes, making it up-to-date for app testing by developers. It is the final preview build before the stable release later this year.
The Android O Developer Preview 4 will be rolled out via OTA to all Google Pixel, Google Pixel XL, Nexus 6P, Nexus 5X, Pixel C, Nexus Player, and Android Emulator users enrolled in the Android Beta Program. If you have a compatible device, then you can register for the beta programme here to receive future OTA beta versions, and the Android O stable version when it releases this fall. Alternatively, you can manually flash system images as well. Remember, installing a system image on a device removes all data from the device, so you should back up your data first. Also, you won’t receive the final Android O build unless you are enrolled in the Android Beta Program.
As we mentioned, Android O Developer Preview 4 is a release candidate build of Android O that you can use to complete your development and testing in time for the upcoming official release. It includes the final system behaviours, the latest bug fixes and optimisations, and the final APIs (API level 26) that app makers can use to test their apps, so that they can be ready as soon as the stable Android 8.0 version drops.
For developers who will indulge in app testing with Android O Developer Preview 4, Google suggests that the developer must ensure that "the app should run and look great, and should handle the Android O behaviour changes properly -- in particular, pay attention to background location limits, notification channels, and changes in networking, security, and identifiers."
Furthermore, to increase engagement within apps and optimise them for battery usage, developers should make use of new Android O features like notification channels and dots, shortcut pinning, picture-in-picture, autofill, adaptive icons, downloadable fonts, autosizing TextView, and optimising your app for background execution limits as well.
The stable build of Android 8.0 will be released alongside the launch of the next generation of Pixel devices. Also, Google will sometime in between also reveal the dessert after which Android O will be named, although there have been some rumours floating around. Let us know of any other new changes you spotted in Android O Developer Preview 4 in the comments below.