Start up project AI-Led Mobile App with Subscription Features

I’m in the early stages of developing a unique, AI-led mobile app focused on gentle personalised interaction. The app will feature:
• A main screen with a Buddha-inspired icon (already designed)
• AI that initiates soft, human-like conversation and encourages ongoing engagement
• A calm, user-led journey designed to adapt over time
• Subscription-based access (multiple tiers)
• Clean, minimalist UI that reflects the app’s peaceful tone

I have:
• The core concept and user journey mapped
• A visual logo ready
• A clearly defined purpose, user flow, and vision for how the app should behave

I’m looking for a developer to:
• Help bring the MVP to life
• Recommend suitable tech stacks (AI integration, backend, UI tools)
• Build a scalable foundation for future features

Ideal experience includes:
• Mobile app development (iOS/Android or cross-platform)
• Experience with OpenAI or similar APIs
• Subscription integration (e.g. Stripe, Firebase, etc.)
• UX/UI sensitivity to deep learning design and personalisation

Please share:
• Examples of similar work
• Your development stack preferences
• Rough cost estimate and timeline
• Any thoughts or questions about the concept

This is a passion project with long-term vision, so I’m looking for someone collaborative and thoughtful.