Taxation Services Android App

I need an Android application that lets my clients handle every routine tax task from a single, simple interface.

Core workflow
• Secure sign-up and log-in with email and password only—no social or guest access.
• A clean, minimal home screen that immediately shows the user’s active GST and Income-Tax jobs, their current status (e.g., “Draft”, “Submitted”, “Acknowledged”), and any pending actions.
• Separate modules for GST Registration & Return Filing and for Income-Tax Filing, each guiding the user step-by-step, saving progress locally and syncing to the server in real time.
• A service dashboard where customers can review completed filings, download acknowledgments, view fee invoices, and raise support tickets.

Design preference
The layout must stay simple and clean: neutral colors, ample whitespace, clear typography, and intuitive navigation patterns following Google Material guidelines.

Typical tech stack I imagine
Kotlin or Java in Android Studio, REST/GraphQL APIs, Firebase (or your suggested alternative) for auth and push notifications. Feel free to propose a different stack if it achieves the same results with equal security and speed.

Deliverables
• Fully functional APK ready for Play-store release
• Complete source code with build instructions
• Database schema and API documentation
• Basic admin or super-user panel (web or in-app) to monitor filings and manage user accounts
• One round of post-launch bug fixing included

Acceptance criteria
1. New user can register, verify email, and reach the dashboard in under two minutes.
2. Filing forms autosave and validate government-mandated fields client-side before submission.
3. Dashboard refreshes status changes without manual reload.
4. App passes Google Play security and performance checks.

Timeline and milestone suggestions are welcome; I am ready to move forward as soon as I see a concise plan.