Kalaam
A React Native and Firebase Quran vocabulary app that teaches Quranic Arabic through spaced repetition, daily challenges, and leaderboards — grown from 10K to 300K+ users over three years.
- App ratings
- 4.8★ on the App Store, 4.7★ on Google Play
- Downloads
- 100,000+ installs on Android
- User growth
- Grew from 10K to 300K+ users over 3 years
- Technical base
- Firebase-backed sync across 80+ languages
Overview
Kalaam is a cross-platform Quran learning app built with React Native and Firebase. It teaches Quranic Arabic vocabulary through spaced repetition, with daily challenges, streaks, leaderboards, and audio recitation, localized into 80+ languages.
I've been a senior engineer on the core team for three years, owning large parts of the React Native UI and the Firebase Cloud Functions backend.
In that time the app has grown from around 10,000 to more than 300,000 users while holding 4.8★ on the App Store and 4.7★ on Google Play.
- Learning, challenge, and leaderboard screens in React Native
- Streak and leaderboard logic on Cloud Functions
- Firestore modeling for offline progress sync
- Release management on both stores
- Ongoing performance and stability work at scale
Screenshots
Challenge
- Make a large, growing content library — vocabulary, audio recitation, and translations in 80+ languages — feel fast on mid-range Android devices and usable offline.
- Keep learner progress, streaks, and leaderboards consistent across devices without expensive Firestore reads on every session.
- Keep shipping on iOS and Android while a small team added features to a codebase used by hundreds of thousands of people.
- Lay a subscription-ready foundation so premium content could be introduced without a rewrite.
Approach
- Built the spaced repetition, daily challenge, and leaderboard screens in a modular React Native architecture with predictable state flows and memoized list rendering for smooth scrolling on low-end devices.
- Wrote Firebase Cloud Functions for streak calculation, leaderboard aggregation, and progress sync so heavy logic runs server-side and the app reads compact, pre-computed documents.
- Modeled Firestore collections for per-user progress with local caching, so reading and review flows work offline and reconcile when back online.
- Optimized navigation, image and audio caching, and content loading for repeat sessions.
- Owned release preparation and store submissions for both platforms, including QA passes and crash monitoring after each release.
Features
- Audio recitation with translation support
- Bookmarks and reading history
- Daily progress tracking
- Search and structured browsing
- Dark and light reading modes
- Subscription-ready content model
- Spaced repetition learning engine
- Localized into 80+ languages, including Urdu, Bengali, and Tamil
- Daily vocabulary and grammar challenges
- Leaderboards and social engagement features
More work
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