I need a full-cycle build of a real-time messaging application for both iOS and Android. The core experience must mirror WhatsApp: • Text messaging with typing indicators, read receipts, and push notifications • One-to-one and group voice calls • High-quality video calls with adaptive bitrate On top of that, the app should support: • File sharing for images, documents, and short videos • Status updates that expire after 24 hours • Group chats with admin controls, mute options, and member invites I expect: 1. UX/UI mock-ups that follow modern Material / iOS Human Interface guidelines. 2. A scalable back-end (Firebase, AWS, or similar) with end-to-end encryption. 3. Native or cross-platform code (Swift/ Kotlin/ Flutter/ React Native); whatever you’re most confident will deliver smooth, low-latency performance. 4. Functional prototype for my review, followed by iterative refinements, testing, and App Store / Google Play deployment. 5. Post-launch support to fix critical bugs during the first release cycle. Hand over clean, well-commented source code, API documentation, and a short user guide so I can manage basic configurations and analytics on my own.