Cross-Platform Music Mobile App -- 2

I am ready to kick off development of a music-centric mobile application that will run natively on both iOS and Android. The core idea is to give users an elegant, reliable way to enjoy music on the go; exact features (think playback, playlist creation, offline mode, user profiles, in-app purchases, social sharing, etc.) will be finalised together once we engage, but the overarching goal is a polished, engaging audio experience that feels right at home on each platform.

Here is what I need from you:

• Technical leadership on the best architecture for a dual-platform build—whether that is Flutter, React Native, Kotlin + Swift, or another proven stack.
• End-to-end development: UI/UX design, frontend implementation, back-end/API integration, testing, and store deployment.
• Clean, well-documented source code I can continue to maintain or hand to another team later.
• Guidance on App Store and Google Play submission, including compliance with their latest audio-streaming and privacy requirements.

Acceptance criteria will be a fully functional TestFlight/Play-Internal build that passes our agreed feature list, along with step-by-step deployment documentation.

If you have shipped music or audio apps before, tell me about it when you respond and include links or package names so I can try them out. I am ready to move quickly once I find the right partner.