Cross-Platform Manga Reader App

Project Overview
A modern, cross-platform mobile app built with Flutter for Android and iOS, focused on manhwa, manhua, and webtoons. Users read content offline after downloading chapters. Monetization via coins (for unlocking chapters) and subscriptions (tiered access), handled through fully custom payment integrations (bypassing Google Play Billing and Apple In-App Purchases entirely for full control and lower fees). Includes a powerful web-based admin panel for content management, user oversight, and transaction handling.
Why Custom Payments?
Complete control over the payment flow and revenue (no platform commissions)
Flexible integration with preferred merchant payment solutions
Supports external payment confirmation (e.g., via callbacks/webhooks) to credit coins or activate subscriptions instantly and securely
Easier to handle refunds, promotions, manual adjustments, and future expansions
Core Features – User Side (Flutter Mobile App)
Authentication & Profiles
Sign up/login via email/password, Google, Apple
Guest mode for free chapters only
Profile section showing favorites, reading history, downloaded content, coin balance, subscription status
Content Discovery & Reading
Home feed: trending, new releases, recommendations, genre browsing
Search by title, author, tags
Series detail page: synopsis, chapter list, status (ongoing/completed)
Smooth vertical-scroll reader with options for theme, brightness, scroll direction
Offline downloads — chapters or full series, with storage management and optional auto-cleanup
Resume from last read position, page bookmarks
Monetization – Custom Payment System
Some chapters free (e.g., initial ones per series)
Coin purchases
Users buy coin packages through custom flow
Locked chapters unlocked with coins (price set per chapter/series by admin)
Bonus coins from daily login or optional rewarded actions
Subscription tiers (recurring monthly/yearly options)
Basic tier: unlimited access to selected titles + bonus coins
Premium tier: broader/unlimited access, ad-free experience, priority features
Custom payment flow (no native IAP):
In-app: select package → generate payment request (e.g., QR code, invoice, link)
User completes payment externally via preferred method
Backend verifies transaction (via webhook/callback/API poll) → credits coins or activates subscription automatically
Secure: tokenized data where needed, no sensitive info stored in app
Fallback options for manual verification (e.g., reference code upload) if required
Additional Features
Favorites/library management
Push notifications for new chapters (Firebase Cloud Messaging)
Dark/light theme support
Basic user comments/ratings (with moderation)
Multi-language readiness (English primary, easy to add others)
Admin Panel (Web-based – can reuse Flutter Web or use React/Node/Laravel/etc.)
Overview dashboard: active users, revenue summary, popular content, transaction stats
Content tools: upload/edit series & chapters, set free/coin/sub access rules, schedule releases
User tools: search users, manage bans, manually add coins/subscriptions
Payment oversight: view transaction logs, handle refunds/manuals, monitor webhook status
Notification sender for broadcasts
Basic reports and analytics
Recommended Technical Stack
Mobile: Flutter (state management: Riverpod or Bloc)
Backend: Firebase suite (Auth, Firestore, Storage, Functions, FCM) or custom (Node.js/NestJS + database like PostgreSQL/MongoDB)
Payments: Custom implementation with webhook endpoints for verification (integrate merchant APIs as chosen later)
Offline handling: dio + flutter_downloader + local DB (Isar/Hive) for chapters/metadata
Reader: custom vertical scrolling widget or extended_image/photo_view packages
Admin panel: Flutter Web (shared code) or dedicated framework