Fireworks Industry Billing Software

I'm looking for a developer to create billing software tailored for the fireworks industry. The software should primarily focus on invoice generation and must support multi-user access.

Key Requirements:
- Invoice Generation: Create and customize invoices.
- Multi-User Access: Allow multiple users to access the system with different permission levels.
- User-friendly interface

Ideal Skills and Experience:
- Experience in developing billing or invoicing software
- Strong background in database management
- UI/UX design skills for creating intuitive interfaces
- Ability to provide a detailed project proposal

Please include a detailed project proposal in your application.