Recall AI – Flutter Flashcard App with AI Generation, Spaced Repetition In-App Subscriptions

Recall AI is a complete, production-ready Flutter application that helps users learn anything faster using AI-generated flashcards and the proven SM-2 spaced repetition algorithm. Built with clean architecture, Riverpod state management, Firebase backend, OpenAI card generation, and RevenueCat subscriptions — everything you need to launch your own study app on Android and iOS.

✨ Key Features

• AI Flashcard Generation — Paste notes, type a topic, or upload a PDF/image. OpenAI (GPT-4o-mini) generates a full deck of flashcards in seconds.
• SM-2 Spaced Repetition — The same algorithm used by Anki. Cards are scheduled at the optimal interval for long-term retention (New → Learning → Review → Mastered).
• 4 Study Modes — Flashcard flip, Multiple Choice (MCQ) with explanations, True/False, and Typing mode (Pro).
• OCR Input (Pro) — Snap a photo or upload a PDF. Google ML Kit extracts the text, then AI turns it into a study deck.
• AI Study Guide — Per-deck AI-generated overview with key concepts, common mistakes, and memory tips.
• Gamification — XP, levels, daily streak tracking with 2× XP multiplier, badges, and mastery percentage per deck.
• Analytics Dashboard — Weekly study chart, subject mastery breakdown, level progress bar, and badge showcase.
• Deck Sharing & Explore — Share decks with a 6-character code. Browse and import from a public community feed.
• Push Reminders — Firebase Cloud Messaging sends daily study reminders to keep users on streak.
• In-App Subscriptions — Free, Monthly, Yearly, and Lifetime tiers managed via RevenueCat with a built-in paywall screen.
• Dark & Light Theme — Material 3 design with dynamic color scheme. Fully customizable brand color.
• 4 Auth Providers — Email/password, Google Sign-In, Sign in with Apple, and anonymous guest mode.
• Offline / Guest Mode — Guests study locally via SharedPreferences. Authenticated users sync via Firestore.
• Portrait-only, phone-first UI — Pixel-perfect Material 3 design with Figtree font.

Screens Included

• Splash Screen with brand animation
• Onboarding carousel (3 slides)
• Sign In / Sign Up (Email, Google, Apple, Guest)
• Home Overview — stats card, recent decks, quick start
• Deck List — search, sort, filter by subject & mastery
• Deck Method Selection — 4 creation modes
• Deck Creation — AI generation form with subject, difficulty, card count
• Deck Detail — 3 tabs: Flashcards, Stats, AI Study Guide
• Deck Edit — add, edit, reorder, delete cards
• Study Session — 4 modes with progress header
• Study Summary — results, XP earned, mastered cards
• Progress / Analytics — level, streak, weekly chart, badges
• Profile — account info, subscription status, quick stats
• Settings — theme toggle, notifications, sign out
• Explore — browse community-shared decks
• Import Deck — 6-character share code lookup
• Paywall — subscription plans with feature comparison

Tech Stack

• Framework: Flutter 3 / Dart 3
• State Management: flutter_riverpod
• Routing: go_router with route guards
• Backend: Firebase Auth, Cloud Firestore, Firebase Remote Config
• AI: OpenAI GPT-4o-mini (key stored in Remote Config — no hardcoding)
• Monetization: RevenueCat (purchases_flutter)
• OCR: Google ML Kit Text Recognition
• Design: Material 3 · Figtree font · Teal seed color (#0D9488)
• Architecture: Clean architecture per feature (presentation / application / domain / data)
• Testing: Unit tests + policy tests included

Subscription Tiers

Free

• Max decks: 5
• Cards per generation: 15
• Character input limit: 2,000
• PDF / Image upload (OCR): ✗
• Typing study mode: ✗
• Deck sharing: 1 deck
• Analytics history: 7 days

Monthly ($4.99)

• Max decks: Unlimited
• Cards per generation: 50
• Character input limit: 20,000
• PDF / Image upload (OCR): ✓
• Typing study mode: ✓
• Deck sharing: Unlimited
• Analytics history: All time

Lifetime ($49.99)

• Max decks: Unlimited
• Cards per generation: 50
• Character input limit: 20,000
• PDF / Image upload (OCR): ✓
• Typing study mode: ✓
• Deck sharing: Unlimited
• Analytics history: All time

⚙️ Requirements to Launch

• Flutter SDK 3.x
• Firebase project (free tier works fine)
• OpenAI API key (added to Firebase Remote Config — no code change needed)
• RevenueCat account (free up to $2,500 MRR)
• Google Play Console ($25 one-time) for Android
• Apple Developer account ($99/year) for iOS + Sign in with Apple

What’s Included

• Complete Flutter source code (Android + iOS)
• Full offline HTML documentation
• Quick Start Guide
• Unit tests + policy tests
• Clean architecture, well-commented and ready to customize