The Android XR ecosystem is experiencing rapid growth with new tooling and expanded engine support. Developer Preview 4 of the Android XR SDK is now available, allowing developers to build and iterate on both immersive and augmented experiences from their laptops. This preview includes libraries for targeting different XR experiences and an emulator in Android Studio for hardware-free testing. The Jetpack Projected library enables developers to extend existing mobile apps for intelligent eyewear, adapting behavior based on device availability. Specialized tools and updated Jetpack Compose Glimmer components facilitate UI building and optimize legibility on optical see-through displays. For immersive experiences, Developer Preview 4 offers Kotlin-first architectural upgrades and an early preview of the Geospatial API for wired XR glasses. This API, combined with ARCore and Google's Visual Positioning System, allows digital content to be anchored to precise real-world locations. Official support has been added for Unreal Engine and Godot, alongside existing Unity support, to ease the transition of existing XR experiences. The Android XR Engine Hub, a desktop tool for Windows, further shortens iteration cycles by enabling real-time testing within engine viewports. The Android XR Developer Catalyst Program is open for applications, offering pre-release hardware and support to selected developers. Developers can begin building now with the Samsung Galaxy XR available and Developer Preview 4 of the SDK. Comprehensive technical sessions are also available on the Android XR YouTube Playlist.