Jewellery Billing Web App Creation

Project: Jewellery Billing Web App I need a premium, modern and responsive web-based jewellery billing application for my business. It should work on both Android phones and Windows laptops/PCs. I have attached a sample bill image. The generated bill should follow a similar professional format. Main Features: 1. Bill Generation - Customer name and mobile/WhatsApp number - Automatic bill/invoice number and date - Item/particulars - Weight - Less - Net weight (automatic) - Labour - Rate - Amount (automatic) - Gold/Silver total - Discount - Bill amount - Cash received - Final balance - Add multiple items 2. Automatic Calculation All calculations should be automatic according to the formulas I provide. Rates and billing settings should be editable by me from the admin/settings panel. 3. Bill Output - Professional bill design - Generate PDF - Print directly - Save/download PDF - WhatsApp sharing Preferred WhatsApp flow: Generate Bill → Generate PDF → WhatsApp → Select Customer → Send PDF 4. Bill History - Save all bills - Search by bill number, customer name/number and date - View/reprint old bills - Download old bills as PDF 5. Shop Settings I should be able to change shop name, logo, address, phone number, bill heading, rates and other basic settings without contacting the developer. 6. Multi-Shop System I may provide this software to other jewellery shops in the future. Please build it as a multi-shop/multi-tenant system. Each shop must have: - Separate login - Separate customers - Separate bills/data - Separate shop name, logo and address One shop must never be able to access another shop's data. I should be able to add new shops without rebuilding the application. 7. Premium UI I want a clean, premium and modern jewellery-business UI, not a basic template. It should be fast and easy for daily billing and responsive on mobile and laptop. 8. Cloud Data & Ownership The application should use a proper cloud database so the same data is available on my phone and laptop. Domain, hosting, database, source code, project files and main admin account must be under my control. I need complete source code and access at final delivery. 9. Low Maintenance Please tell me the expected yearly cost for domain, hosting, database and any other services. I want minimum ongoing maintenance and no hidden developer dependency. 10. Milestones I prefer milestone-based development: - UI + bill design - Calculations + PDF/printing - Database + bill history - Multi-shop + admin panel - WhatsApp + final deployment/testing Final payment will be released only after I receive and test the complete working project on both phone and laptop. Before starting, please send: - 2–3 similar projects you personally developed - Proposed technology/stack - Total cost - Timeline - Hosting/database requirements - Yearly running cost - Confirmation that I will receive complete source code and ownership/access Please discuss and finalize the calculation formulas with me before development starts. Scalability & Storage: The application should be designed to support a growing number of shops and bills without requiring a complete rebuild. There should be no unnecessary hard-coded limit on the number of shops or bills. Bill data should be stored efficiently in a scalable cloud database. PDFs should preferably be generated on demand rather than permanently storing every PDF unless required. Please specify the expected database/storage capacity, current hosting limits, approximate number of shops/bills the proposed setup can support, and how upgrading will work if the application grows.