Medium-Sized ERP Online System Development

I'm seeking a professional developer to create a comprehensive ERP online application. The system should have the following key features:

- Inventory Management: A robust system to handle stock, orders, and product information efficiently.
- Sales and Order Management: A sales module for processing orders, tracking sales, and managing customer invoices.
- CRM: A Customer Relationship Management system to help us maintain and improve our relationships with clients.
- POS: A Point of Sale system to enable easy and professional transactions.
- Payment Gateway: Integration with a secure payment gateway for seamless transactions.
- User Roles: A multi-tier system with Super Admin, Admin, and User roles.

The target audience for this application is medium-sized enterprises, thus it should be scalable, user-friendly, and capable of handling a moderate amount of data.

Platform Compatibility:
- The ERP application should be compatible with web browsers, allowing users to access it through their desktop or laptop.
- It should also be compatible with Android and iOS devices, enabling easy access on mobile devices.

Ideal skills for the job include:
- Proficiency in ERP system development.
- Experience in designing and deploying POS systems.
- Extensive knowledge of CRM systems.
- Previous experience in e-commerce and payment gateway integration.
- Strong UI/UX skills for creating a user-friendly interface.
- Experience in developing cross-platform applications for web, Android, and iOS.