Flutter Android App for WordPress Website (API-Based, Fully Synced)

I am looking for an experienced Flutter developer to build an Android mobile application for my existing website: https://trustserve.store.

The app must NOT be a WebView. I need a proper Flutter-based mobile application that is fully connected to my WordPress backend using REST API, so that all data between the website and the app stays completely synchronized.

Project Overview:
My website is a real estate and classified listings platform (similar to OLX). The mobile app should act as a frontend and fetch/send all data from/to the website database via API.

Core Requirements:

- Develop a Flutter-based Android app
- Integrate with WordPress REST API
- Fetch listings, categories, and user data from website
- Allow users to post ads (data must be stored on website)
- User authentication system (Google Sign-In + mobile OTP preferred)
- User profile section (manage listings, account details)
- Search and filter functionality
- Clean, modern, and fast UI/UX

Additional Features (Preferred):

- Push notifications (Firebase)
- Favorites / saved listings
- Basic in-app chat between users

Technical Notes:

- Website backend is already built on WordPress
- Developer should handle API integration properly
- App should be scalable and well-structured

Deliverables:

- Complete Android APK
- Source code (Flutter project)
- Proper API integration
- Basic documentation

Timeline:
3–5 weeks

Budget:
Open to reasonable proposals based on experience and quality.

Please share your portfolio or previous similar work (especially marketplace or real estate apps).