Infinite Math vs Chess Notation Fluency

That “I solved it!” feeling, all over again. A math app for grown-ups who solve for pleasure—not for any exam. From the wonder of primes and divisors to the crane-and-turtle puzzle, the Monty Hall problem, and even the legendary entrance exams of Japan's top universities— a collection of beautiful problems that make you feel "numbers are fascinating." ■ Made for you if you ・love numbers and logic puzzles ・enjoy giving your mind a workout in spare moments ・want to know not just the answer, but the idea behind it ・are done with exams, but want to rediscover the joy of math ■ Six categories, 55+ problems (more added over time) ・Number Theory & Puzzles … primes, divisors, Fibonacci, perfect numbers, and more ・Classic Problems … crane-and-turtle, Monty Hall, the Königsberg bridges, Pick's theorem, and more ・Elementary Exams … ferris-wheel logic, seesaw puzzles, and other gems ・Junior-High Exams … work, travel, concentration, and counting problems ・High-School Exams … symmetric expressions, probability, Euler's prime-generating formula ・University Exams … legendary stumpers like "Is tan 1° rational?" and "Prove π > 3.05" ■ Highlights ・Daily Problem … one fresh problem to tackle each day ・Sessions … test yourself with five problems at a time ・Explanations worth reading … not just the answer, but the background and the thinking ・Interactive figures … trace the Königsberg bridges or Pick's theorem with your finger ・Progress tracking … solved problems are recorded; aim to clear them all ・19 languages … enjoy these problems in Japanese, English, Chinese, Korean, and more Answers are simple multiple choice—and some figures come alive at your fingertips. Enjoy the world of numbers on your commute, on a break, or before bed.

Make chess notation feel natural. Chess Notation Fluency helps you read and write Standard Algebraic Notation (SAN) through focused practice with real game sequences. TRAIN IN BOTH DIRECTIONS • Watch a move on the board, then enter its notation. • Read a notation prompt, then play the move. • Use Mixed practice to alternate naturally between the two skills. PRACTICE YOUR WAY Choose White or Black, type answers or use multiple choice, begin in the opening, middlegame, or endgame, and select a quick session or a complete game. Exercises retain the surrounding moves so you practice notation in context—not as isolated flash cards. LEARN FROM YOUR RESULTS Track first-try accuracy, attempts, response time, revealed answers, notation features, mistake patterns, and recent sessions. START FREE. EXPAND ONCE. Every practice mode works with two included starter games. An optional one-time Full Game Library purchase unlocks 5,000 curated games for offline practice and lets you import your own PGN games. One purchase unlocks the library on iPhone, iPad, and Mac and supports Family Sharing. There are no subscriptions or ads. PRIVATE AND AVAILABLE Practice history and imported games stay in app-managed storage and synchronize through your private iCloud storage when available. Downloaded content works offline. Chess Notation Fluency has no developer account system and collects no personal data. Available on iPhone, iPad, and Mac.