I need a full-featured VPN application built for Android. The goal is to give end-users a simple, reliable way to secure their mobile traffic, hide their IP address, and connect through encrypted tunnels at the tap of a button. You will handle everything from crafting a clean, modern UI that follows Google’s design guidelines to integrating the core VPN engine and managing connections in the background so users stay protected even when the app is not in the foreground. The build should support current Android versions, respect battery and data limits, and pass Play Store compliance checks, including the new VPN service requirements. Source code (Kotlin or Java), signed APK / AAB files ready for publishing, and concise setup documentation are the key deliverables. Please structure the project so that server credentials and endpoints can be changed easily without a full recompilation. Once completed, I’ll test performance, connection stability, and overall user experience on a range of devices before marking the milestone complete.