Riichi Sensei vs Quarry

Riichi Sensei scores riichi mahjong hands, teaches the yaku and quizzes you on yaku, scoring and waits, by the rules you play. No ads, nothing collected, scoring you can trust • No ads, no account and no tracking. The app works offline and collects nothing. • Every score follows the rules exactly. The scoring is checked against the European Mahjong Association's 2025 and 2016 rulebooks, section by section. Score a hand • Tap tiles on a keyboard made for the job. Chi, pon, kan and a closed kan take a tap each. • The score follows every change: what the winner announces ("2,000/4,000", "4,000 all"), the han and fu, and the limit. • Choose ron or tsumo, riichi, your seat and the round in one place. A short guide and a sample hand show the way. • See how the points are worked out: each yaku and its han, what each group of tiles earns in fu, the wait, and the rounding. • At the table: who pays what, with counters, riichi sticks and liability. • A hand with no yaku? It says what would give it one. Four rule sets • EMA 2025 for European tournaments, EMA 2016 for clubs that still play it, WRC 2025 for the World Riichi Championship, and Mahjong Soul's ranked rules, each with its own red fives, rounding and yakuman. Learn • A points table for every han and fu, under the rules you choose. • Every yaku with its English and Japanese names, the rules with their place in the EMA rulebook, tips, common mistakes, and example hands that open in the calculator. Practice • Name the yaku: find every yaku in a winning hand, and see what each is worth and what the ones you missed need. • Score this hand: count the han and the fu, call the points, and see why each answer is right. • What's the wait? Find every tile that completes the hand, in everyday hands or one-suit ones. • A hand you get wrong comes back a few hands later, until you get it right. Your progress stays on your device. For phones and tablets • Light and dark themes, large text and screen readers, and two panes on a tablet. • In English, German, Spanish, Portuguese, French and Russian, as your device is set or as you choose.

Data interview practice that runs entirely on your device. Write real SQL and Python (pandas), get graded instantly, and see exactly why. NEW IN 1.2 • Today's problem: one problem a day, on Home and in a new widget for your Home Screen and Lock Screen. • Streaks and a daily goal: solve something every day and watch the streak grow. • An optional daily reminder, off unless you turn it on. • 20 new problems: A/B tests, attribution, quartiles, pivots, rate limiters and more. • Make it yours: six accent colours and four code editor colour schemes. • Quarry Pro: every Medium and Hard problem, a review queue that brings back the problems you found hard, and every future problem pack. WHAT'S INSIDE • 188 problems across three tracks: SQL, pandas and Python (algorithms and data structures). • Real execution, real grading. Your output is checked against the expected result, with no self-marking. • Company-style practice. Filter problems written in the style of the company you're interviewing at. • Hints and full solutions when you're stuck. • Difficulty levels from Easy to Hard, grouped by topic. • A free-form Playground for scratch SQL and Python. • Designed for iPhone, iPad and iPhone Duo. FREE AND PRO Every Easy problem, a sample of Medium ones, the daily problem, streaks, the widget and the Playground are free. Quarry Pro unlocks the other 119 problems, the review queue and every future pack. Quarry Pro is available monthly or yearly (auto-renewing), or as a one-time lifetime purchase. Payment is charged to your Apple Account. Subscriptions renew automatically unless cancelled at least 24 hours before the end of the current period; manage or cancel them in your Apple Account settings. PRIVATE BY DESIGN No accounts. No analytics. No ads. No tracking. Quarry collects nothing and works fully offline. Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://mayankgulaty.github.io/quarry-site/privacy.html Built by a working data engineer, for analysts, data engineers, data scientists and software engineers who want a quiet, fast place to actually practice.