Build Social Messaging App

I need a complete mobile social-media style application whose first release focuses on real-time messaging between users. The goal is to publish on both iOS and Android, so cross-platform frameworks such as Flutter or React Native are preferred, but I am open to a truly native build if you can justify the benefit.

Core deliverable
• Secure, reliable messaging system that supports text, images, and push notifications.

Around that core you may propose lightweight profile and news-feed stubs for future expansion, yet the messaging experience must ship first and feel polished. I will provide wireframes and basic brand assets; you will handle UX refinement, API design, backend (Firebase, Supabase, or a comparable real-time service), and store submission support.

Please outline:
– The tech stack you recommend and why
– A milestone plan from prototype to store release
– Any previous chat or social apps you have shipped

Clean, maintainable code and clear documentation are essential for hand-off to my in-house team once we move beyond v1.