E-commerce Mobile App Development

I'm looking for an experienced developer to create an mobile as well as website application for my e-commerce website. The app should have three key roles: Admin, Vendor, and User.

Essential functionalities include:
- Product listing and management
- Shopping cart and checkout

Ideal skills and experience:
- Proven experience in mobile app development, specifically for web and mobile
- Strong understanding of e-commerce functionalities
- Ability to implement role-based access and management

Please provide samples of previous work and a timeline for completion. Looking forward to your bids!