Urgent required Professional Android App Development

I'm in need of a skilled Android developer to build a professional, corporate-styled e-commerce mobile app. The app must come with an admin panel for managing different roles (manager, supervisor, vendor) and should allow supervisors to create vendors and customers. Key features include:

- User-friendly Interface: The app should have a polished, professional, and corporate design.
- Product Catalog: A simple category and subcategory system for product organization.
- Product Search and Filtering
- Shopping Cart
- Secure Payment Gateway Integration
- Order Tracking

The ideal candidate for this medium-sized project (1 month duration) should be proficient in the following skills:
- Android App Development
- Java or Kotlin
- UI/UX Design
- Firebase or other backend integration
- Payment Gateway Integration
- API Integration

User authentication for the app should follow a simple system where users are generated and given custom passwords. An experience level of intermediate or higher is preferred.