Comprehensive Web & Android Billing Software

I'm seeking an experienced software developer to create a comprehensive billing software compatible with both web and Android platforms. The software should encompass a variety of features including:

- Customer Management: Handling billing, an ordering page, and payment processing
- Invoice Management: Generating bills, quotations, purchase orders, proforma invoices, managing vendors, and automatic e-way generation
- Price List Maker
- Product Management
- Inventory Management
- Role-Based Access: Different roles for Accountant, Vendor, and Electrician with a referral and earning system
- Coupon System
- Payment Gateway Integration
- Staff Management: Handling roles, attendance, and salary
- Voice Enablement: Using Alexa for bill generation, statement dispatch, and price list creation in both Hindi and English

The ideal candidate should have:
- Proven experience in developing billing software
- Proficiency in web and Android app development
- Strong understanding of customer and invoice management features
- Skills in implementing role-based access in software
- Experience with payment gateway integration
- Knowledge in voice enablement of software

Please provide examples of similar projects you've completed when bidding.