GST Billing Software & Panel

I need a lightweight GST-compliant billing solution tailored for a service-based business. The system should include both a web-based admin panel and an Android APK so that I can create invoices from my laptop while my staff can do the same from their phones... (Budget: ₹1500 - ₹12500 INR, Jobs: Android, Android App Development, Angular, Mobile App Development, MySQL, PHP, Software Architecture, Web Development)