I need a clean, production-ready Android application built from the ground up. The core scope is straightforward: design an intuitive UI, develop the full codebase, and implement secure user authentication so people can sign up, log in, and manage their session reliably. The ideal flow is: wireframes → polished UI mock-ups → iterative development in Android Studio (Java or Kotlin) → unit/UI testing → a signed APK and readable source code in a Git repository. Feel free to leverage Firebase Auth, OAuth2, or another standards-compliant solution for the login layer as long as it keeps credentials safe and supports email-password plus social sign-ins. Right now I only need the Android version; however, structuring the project so it can later be extended to iOS—or augmented with push notifications and in-app purchases—will earn extra points. Clear documentation of architecture decisions, third-party libraries, and build steps must accompany the final delivery. Deliverables: • Interactive UI/UX mock-ups • Complete Android Studio project with commented code • Integrated, fully tested user authentication flow • Signed release APK + Play Store-ready assets • Setup & build guide (Markdown or PDF) I’ll review work in two milestones—design first, then functional build—so I can give feedback early and keep us both on track. Let me know which authentication stack you prefer, any relevant apps you’ve shipped, and your estimated timeline to hit both milestones.