GST Billing App & Panels

I need a GST-compliant billing solution delivered as a ready-to-install Android APK, supported by a user panel and an admin panel. Core flow The app must let a user create a GST invoice in seconds and instantly turn it into a shareable / printable PDF... (Budget: ₹600 - ₹1500 INR, Jobs: Android, Android App Development, Java, Laravel, Mobile App Development, Node.js, PHP, Software Architecture)