Android Business App Development

I need an experienced Android app developer from Rajasthan to create a business application. The app should include:

- User Login: Secure authentication for users.
- Payment Integration: Enable seamless transactions.
- User Roles: Implement role-based permissions for different users.

Ideal Skills:
- Experience with Android app development
- Expertise in secure login and payment integration
- Ability to implement user roles and permissions

Please provide examples of previous work.