Google today launched the fourth and final Android O developer preview, available for download now at developer.android.com and via the Android Beta Program. The preview includes an updated SDK with system images for the Nexus 5X, Nexus 6P, Nexus Player, Pixel, Pixel XL, Pixel C, and the official Android Emulator, and there’s even an emulator for testing Android Wear 2.0 on Android O. In addition to the usual bug fixes and optimizations, this preview has the final system behaviors (the APIs were made final in the third preview), meaning there won’t be any major changes between now and the final release.

Google launched the first Android O developer preview in March, the second developer preview in May at its I/O 2017 developer conference, and the third developer preview in June. Google has slated the final version for release “later this summer” (in Q3 2017).

Android O offers of a slew of new features including background limits, notification channels and dots, Autofill APIs, Picture in Picture, XML font resources, downloadable fonts, emoji compatibility, autosizing textview, adaptive icons, Webview enhancements, AAudio API, high-quality Bluetooth audio codecs, wide-gamut color for apps, and Google Play Protect, as well as Java 8 APIs and runtime optimizations. Google is also promising OS optimizations that should lead to faster boot times and smoother apps.

Developer Preview 4 is a release candidate build of Android O that developers can use to complete their apps and testing in time for the official release.

You can download the final API 26 SDK from the SDK Manager in Android Studio. Google is also releasing the stable version of the Android Support Library 26.0.0 (available from its Maven repository) and a new version of Android Testing Support Library that brings features like Android Test Orchestrator and Multiprocess Espresso.

This should give developers everything they need to develop and test their apps for Android O (migration guide). If you’re building an app, check the Android O behavior changes to make sure your app is handling them correctly. You may also want to publish your APK updates in your alpha, beta, or production channels with the current targeting level, so that they’re available as users start to receive Android O.

For those wondering if Google will be sharing the Android O name today, you’re out of luck — a Google spokesperson confirmed with VentureBeat that the company isn’t even giving a concrete date for the announcement. But, there’s a new octopus Easter egg when you vigorously tap on the Android version in system settings.