Cross-Platform Mobile App Development

Description:

I am looking for an experienced developer to create a cross-platform mobile application using Flutter and Kotlin for native Android development. The application will have the following features:

Cross-Platform Development with Flutter:

Develop the core of the app using Flutter to ensure it runs on both iOS and Android.
Ensure smooth UI/UX that adapts to different screen sizes and orientations.
Native Android Development with Kotlin:

Use Kotlin for specific features or functionalities that require native Android performance.
Handle Android-specific tasks such as background processes, services, or native integrations.
Key Features:

Login & Registration: Implement Firebase or a similar service for authentication.
API Integration: Fetch data from an external API and display it in the app.
Offline Mode: The app should store some data locally to allow offline use.
Push Notifications: Use Firebase for sending push notifications.
In-App Purchases: Implement in-app purchases for premium features.
Real-time Data Sync: Ensure real-time data sync between users.
Design:

I will provide a basic wireframe or design mockups, but I expect you to improve or suggest changes for a better user experience.
Timeline:

The project needs to be completed within X weeks. Please provide a realistic timeline for development and testing.
Skills Required:

Proficiency in Kotlin for native Android development.
Expertise in Flutter for cross-platform mobile development.
Experience with Firebase or other backend services.
Ability to work with REST APIs and handle data efficiently.
Communication:

Regular progress updates are required, with weekly or bi-weekly check-ins.
Open to feedback and iteration to ensure the app meets my requirements.
Deliverables:

Complete source code for both Flutter and Kotlin components.
Documentation on how to run and maintain the app.
APK file for testing on Android, and assistance with app store submissions.