Cross-Platform Prayer App Build

I’m ready to create a new prayer and meditation app for both iOS and Android. The closest example of what I have in mind is Hallow—please review it here:

iOS: https://apps.apple.com/us/app/hallow-prayer-meditation/id1405323394
Android: https://play.google.com/store/apps/details?id=app.hallow.android

Functionally, I want to replicate the smooth user flow, session library structure, and overall polish of Hallow while replacing all of the audio, text, and video with my own content. The interface should feel modern and sleek, with clean typography, subtle animation, and an intuitive navigation pattern that makes it effortless for users to move from daily prayer sessions to longer-form meditations.

Key deliverables
• A production-ready iOS build that meets current App Store guidelines
• A production-ready Android build compliant with Google Play requirements
• A lightweight content-management approach so I can update prayers and meditations without pushing new binaries
• Secure user accounts (email, Apple, Google, or similar) and cloud sync of progress

I will supply all branding assets and content; you bring the technical architecture, UI/UX implementation, and end-to-end testing. If you have experience cloning complex feature sets cleanly, especially in Flutter or React Native, please outline your preferred stack and timeline when you respond.