lemma vs Tally

Train like a quant. Daily. Lemma is the focused, no-fluff prep app for quantitative interviews — built for students and grads targeting Jane Street, Citadel, Optiver, Two Sigma, and the rest of the trading-firm gauntlet. WHAT'S INSIDE WITH YOUR SUBSCRIPTION • Daily sprints — bite-sized timed sets of mental math, probability, combinatorics, expected value, and market-making problems • Per-category ELO — your skill is tracked across 10 disciplines, from Novice to Expert • Adaptive difficulty — problems chosen to keep you at the edge of your level, not above or below • Hints + step-through solutions — get unstuck without giving up • Streaks, XP, leagues — habit loops without the noise • Achievements — unlock as you grind • Leaderboard — see how you stack up WHO IT'S FOR • CS / math undergrads applying to trading firms • Recent grads prepping for technical interviews • Self-learners who want a daily quantitative-thinking habit • Anyone curious about how trading interviews actually feel WHY LEMMA We strip out the gamified clutter and keep what matters: hard problems, fast iteration, real numbers on your progress. The interface borrows more from a Bloomberg terminal than a typical mobile game — monospaced metrics, hairline borders, dark by default. Most prep books drown you in 800 pages. Most courses lock you in for months. Lemma is 10 minutes a day, sharpened every day. — Lemma offers an optional auto-renewable subscription for unlimited daily sprints and premium problem sets. Subscriptions auto-renew unless cancelled at least 24 hours before the end of the current period. Manage or cancel anytime in your Apple ID settings. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://rogeru13.github.io/lemma-legal/privacy-policy/

Tally makes you faster at mental math — genuinely, measurably faster — with a few focused minutes a day. No childish games, no ads, no accounts. Just a beautifully quiet training room, an adaptive engine, and numbers that start obeying you. TRAINING THAT FITS YOU Every mode tracks its own skill rating. Answer quickly and correctly and the problems grow harder; struggle and they ease off. Tally aims to keep you around 80–85% accuracy — the zone where practice feels challenging, never punishing. A five-problem calibration on first launch means even your first session fits. EIGHT MODES • Add & Subtract — from single digits to four-digit carrying • Multiply — tables through two-by-two digit products • Divide — exact division, then remainders (real mod arithmetic) • Percentages — always exact, never rounded lies • Fractions — add, compare, simplify • Squares & Roots — squares to 25², perfect roots • Powers of 10 — the decimal-shifting reflex • Mixed Gauntlet — everything, blended FIVE WAYS TO TRAIN • Practice — ten adaptive problems, untimed • Sprint — 60, 120, or 180 seconds against the clock • Zen — endless, no score, ambient calm • Gauntlet — twenty problems, three lives, rising difficulty • Daily Challenge — ten problems, date-seeded, the same ten for every Tally user on Earth. Compare your standing when you finish. PROGRESS YOU CAN SEE XP, levels, and ranks from Novice to Grandmaster. A skill graph per mode. Speed trends, your weakest operations detected automatically, and a training heatmap. After every session, a magazine-style review shows each problem, your time, and the mental-math trick you could have used. A STREAK WORTH KEEPING The ember on your home screen grows with your streak — 7, 30, 100, 365 days. Miss a day as a Pro member and a Streak Freeze covers it automatically, two per month. Reminders are gentle, optional, and honest. DESIGNED LIKE IT MATTERS Typography-first interface. A flagship dark mode. Custom haptics on every key. Subtle Metal-rendered moments when you get it right. Full Reduce Motion support. No third-party code, no analytics SDKs — your data never leaves your device. FREE VS PRO Free forever: Add & Subtract, Multiply, and Percentages practice, Zen mode, the Daily Challenge, one Sprint a day, streaks and levels. Tally Pro unlocks all eight modes, unlimited Sprints, the Gauntlet, full statistics, manual difficulty and exam presets (GMAT, GRE, aptitude), and automatic Streak Freezes. Monthly, annual (7-day free trial), or a one-time lifetime purchase. Subscriptions Details -------------------- Subscription | Validity Period | Price ----------------------------------- Pro Lifetime | Lifetime | $39.99 Pro Monthly | 1 Month | $3.99 Pro Annual | 1 Year | $24.99 Two minutes a day compounds. Start today. Privacy Policy: https://www.mindzbase.com/privacy-policy Terms of Use: https://www.mindzbase.com/terms-of-use