The Mahj Index: Mahjong Coach
Built for American Mahjong.
Only for iPhone
Free · In‑App Purchases · Designed for iPhone. Not verified for macOS.
iPhone
The Mahj Index is built for American Mahjong players who want to practice smarter, track their play, and improve every time they sit down at the table.
Drills take minutes. Logging a game takes seconds. And every result feeds a player rating that shows how you actually play (not how you think you play).
Unlike traditional Mahjong apps, The Mahj Index doesn't replace your table. It helps you get more from every game you play.
DAILY PRACTICE THAT FITS YOUR SCHEDULE
Train one skill at a time with quick interactive drills designed for American Mahjong.
• Form a Winning Line: Build valid hands using the current National Mah Jongg League card.
• Mahjle: Solve the daily pattern recognition challenge.
• Charleston: Practice stronger passing decisions.
• Reading Exposures: Learn to recognize what the table is telling you.
Receive instant feedback after every drill. AI Scrimmages and Pivot Practice are coming soon.
TRACK EVERY GAME
Log hands in seconds.
TMI automatically calculates scores, payouts, standings, and statistics for both Friendly Stakes and Tournament scoring.
No spreadsheets.
No calculators.
No keeping score by hand.
MEASURE REAL PROGRESS
Your TMI Rating measures your performance using Glicko-2, the same rating system family trusted across competitive games.
Every game is verified by the other players at your table, helping keep ratings accurate and meaningful.
Your MHIN is your permanent player profile, making it easy to track your progress wherever you play.
KNOW YOUR GAME
Understand how you actually play.
Track your:
• Win rate over time
• Favorite lines
• Wall games
• Playing style
• Mahj Persona
See your strengths, spot your patterns, and always know what to practice next.
PLAY WITH YOUR PEOPLE
Host games, invite friends with a code or QR, and build a shared history together.
See who you play with most, compare results over time, and settle the rematch.
FREE TO JOIN
Create your MHIN, host games, log scores, and start building your TMI Rating for free.
TMI Premium unlocks the complete practice library, advanced analytics, and your full game history.
Players who join with a friend's referral code receive 30 days of Premium at no cost.
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Built for American Mahjong using the current National Mah Jongg League card, updated annually. The Mahj Index is an independent app and is not affiliated with or endorsed by the National Mah Jongg League (NMJL).
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Questions? support@themahjindex.com
Privacy Policy: https://themahjindex.com/privacy
Terms of Use: https://themahjindex.com/terms
Play at a higher level with 1.1.0:
- Scrimmage: play a full game against three bots, from the first Charleston to the final discard.
- New members: everything is unlocked free for your first 7 days. No credit card, no strings.
- The Learn module now links straight into practice: drill what you just learned.
- Sharper stats, smoother streaks, and fixes throughout.
The developer, The Mahj Index, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Linked to You
The following data may be collected and linked to your identity:
- Purchases
- Location
- Contact Info
- Contacts
- User Content
- Identifiers
- Usage Data
- Diagnostics
- Other Data
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- The Mahj Index LLC
- Size
- 39.9 MB
- Category
- Utilities
- Compatibility
Requires iOS 15.1 or later.
- iPhone
Requires iOS 15.1 or later. - iPod touch
Requires iOS 15.1 or later. - Mac
Requires macOS 12.0 or later and a Mac with Apple M1 chip or later. - Apple Vision
Requires visionOS 1.0 or later.
- iPhone
- Languages
- English
- Age Rating
18+
- 18+
- Infrequent
Contests
Contains
Gambling
- In-App Purchases
Yes
- TMI Premium Annual $49.99
- TMI Premium Monthly $4.99
- Copyright
- © 2026 The Mahj Index LLC