I’m building an Android-based jejaring sosial that revolves around real-time conversations. The core of the project is an APK that delivers smooth pesan instan functionality—think quick one-to-one chats and responsive group threads—wrapped in a familiar social-network experience (profiles, friend lists, basic feed). Here’s what I need from you: • A production-ready Android application (latest stable SDK) with instant-messaging as its flagship feature. • Clean, well-documented Kotlin or Java code plus any accompanying backend setup (Firebase, Node, or another solution you prefer), so I can maintain and scale the service later. • Basic UI that follows modern Material guidelines; polished enough for internal testing yet flexible for future visual upgrades. • A brief hand-over guide covering build steps, environment variables, and how to push the app to Google Play when the time comes. Acceptance criteria: messages deliver in under two seconds on a typical 4G connection, users remain signed in across sessions, and the APK installs without warnings on Android 8-14 devices. If you’ve shipped chat-centric apps before and can turn this vision into a reliable APK, let’s get started.