Interactive story app that will make a million+

This project is an immersive, mobile interactive-fiction experience built around a dark, erotic-romance plotline. The core narrative has to branch in meaningful ways, giving readers multiple paths and endings while letting them shape their own protagonist through rich character-customisation options.

Key requirements
• A clean, performant app for iOS and Android using a framework that supports complex branching (Unity, Flutter, React Native or similar).
• A subscription-based in-app purchase system that unlocks new chapters, routes and premium cosmetic options. Apple and Google purchase flows must be fully implemented and sandbox-tested.
• An easy-to-expand story engine so fresh episodes or side stories can be dropped in without refactoring existing code.
• Character-customisation tools (appearance, name, a few trait sliders) that feed back into dialogue and romance outcomes.
• Content and save data should persist seamlessly across devices when a user signs in.
• Analytics hooks so I can monitor chapter completion and purchase conversion.

Deliverables
1. Source code, build instructions and all project assets.
2. A working TestFlight / internal track build demonstrating multiple storylines, character customisation and the subscription paywall.
3. Documentation on adding new chapters, localising text and managing live operations.

Acceptance criteria
• Smooth navigation with no dead ends or broken branches across every tested path.
• Subscription flow approved in both App Store and Google Play test review.
• All configurable copy and artwork externalised for future updates.

The storytelling, artwork and dialogue are handled on my side; what I need from you is the complete technical framework that turns that content into a polished, revenue-ready app.