The challenge
Small businesses in India have to issue GST-compliant invoices every day, but most billing software is built for accountants, not shop owners. Owners were writing bills by hand or in spreadsheets, calculating CGST, SGST and IGST manually, and losing track of what was sold and bought.
The brief was simple: make GST billing fast enough to do at the counter, on a phone, without any accounting knowledge.
What we built
- GST invoices in a few taps, with CGST, SGST and IGST calculated automatically from each product's rate.
- Sales and purchase records in one place, with sale, purchase and quotation bills.
- Customers, suppliers and products saved once, so repeat billing takes seconds.
- Live stock levels that flag low-stock products before they run out.
- PDF invoices to download or share straight to WhatsApp and email.
Tech stack
01Interface
- React NativeAndroid & iOS apps
02Backend
- Node.jsAPIs & business logic
03Data
- MongoDBPrimary database
04Cloud & services
- AWSHosting & storage
Architecture
- Clients
- Android app
- PDF invoices
- WhatsApp & email sharing
- Services
- Invoices & bills
- GST calculation
- Parties & products
- Data & infra
- MongoDB
- Secure storage
- AWS hosting
Screens
Sales, purchase and quotation bills 
Products with live stock levels 
Customers and suppliers 
Product details
Results
InvoiceGen is live on Google Play with 500+ downloads and a 5.0 rating.
