I need a skilled mobile app developer to create an e-commerce app with the following requirements: Core Features: - User Authentication: Secure login and user management. - Product Catalog: Comprehensive listing of products. - Shopping Cart/Checkout: Seamless shopping experience. Payment Methods: - Cash on Delivery - QR Code Payments Ideal skills and experience: - Expertise in mobile app development (iOS and Android) - Experience with e-commerce applications - Strong knowledge of secure payment integration and user authentication protocols - UI/UX design skills for an intuitive user experience Please provide a portfolio with relevant work. Looking forward to your proposals!