For those developers interested in Android, Developer Preview 4 for Android O is now available. This is the final preview before the latest version of Android launches; as a result, if you build Android apps, you should probably check this out if you want to preview and test features. Developer Preview 4 includes bug fixes and updated APIs. Google has tried to refine the development process via the Android Beta Program, which sends an over-the-air Preview update; from there, developers can download their current app from Google Play in order to test the UX and features. “The app should run and look great, and should handle the Android O behavior changes properly,” mentioned a note in Google’s Developers Blog. “In particular, pay attention to background location limits, notification channels, and changes in networking, security, and identifiers.” Android O features include downloadable fonts, adaptive icons, and optimized battery life (with background execution limits). If you haven’t started building Android apps yet (but the idea interests you), the latest version of Android Studio 3.0 has some new tools and toys for developers. These include an SDK for Instant Apps, in which users can run apps without needing to install anything. There’s also support for the Kotlin programming language, which has seen its popularity climb over the past several months. Despite a bit of UX roughness in its early years, not to mention the fragmentation issues that come with a massive third-party hardware ecosystem, Android is now a polished OS; the next battle centers on artificial intelligence and machine learning. Google is betting big on Assistant and other functionality that leverages user data to provide smartphone owners with timely, actionable information. This fall, Android O will find itself going head-to-head against Apple’s Siri, the digital assistant woven deeply into iOS. But A.I. alone won't sell the platform; for Android to maintain its massive market-share, it needs cool apps. And that's where third-party developers come in.