QuantDojo vs lemma
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
QuantDojo
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QuantDojo is the only app built specifically for quant finance interview prep. 1,300+ brain teasers and growing, covering every question type you'll face at top firms. WHAT YOU GET • 1,300+ brain teasers across Probability, Statistics, Combinatorics, Logic, and Game Theory • Questions tagged by firm — Jane Street, Citadel, Two Sigma, DE Shaw, Optiver, SIG, HRT, IMC, and more • 3 progressive hints per question to guide your thinking • Full step-by-step solutions with mathematical explanations • Spaced repetition to lock in what you've learned • Track your accuracy by category and difficulty HOW IT WORKS Pick a category, difficulty, or target firm and start solving. Reveal hints when you're stuck. Check the full solution when you're ready. Mark questions as solved or send them to your review queue. QuantDojo tracks your weak spots and resurfaces questions at the right intervals. WHO IT'S FOR • Students prepping for quant interviews • Career switchers moving into quant finance • Working professionals staying sharp PRICING Subscribe monthly or annually, or get lifetime access with a single purchase. Free users can preview 3 full solutions before subscribing. Privacy: All your data stays on your device. We collect nothing. Terms of Use: https://elilindt.github.io/quantdojo-site/terms.html Privacy Policy: https://elilindt.github.io/quantdojo-site/privacy.html
lemma
This app provides focused, daily practice for quantitative interviews, featuring timed sprints of math and probability problems. It tracks your skill across disciplines with adaptive difficulty and offers hints and solutions to help you improve. Designed for those preparing for trading firm interviews or seeking to build a quantitative thinking habit.
- Daily timed problem sprints
- Per-category ELO skill tracking
- Adaptive difficulty
- Hints and step-through solutions
- Streaks, XP, and achievements
- Leaderboard
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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/
Screenshots
Verdict
The clearest difference is iOS requirement: lemma at 15.1 against QuantDojo's 17.0. On price, ads, in-app purchases and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. QuantDojo sells 3 in-app purchases, starting at $12.99 per month and lemma sells 3 in-app purchases, starting at $6.99 per 7 days. Whichever you choose, the download price is not the number that matters.
| Parameter | QuantDojo | lemma |
|---|---|---|
| Price | Free | Free |
| Rating | — | 5.0 (1 ratings) — better |
| Number of ratings | — | 1 — better |
| Update frequency | — | Every 3 days |
| Ads | No | No |
| In-app purchases | Yes | Yes |
| Monetization | — | Free with in-app purchases |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.0 | 15.1 — better |
| Further details — not scored | ||
| Size | 3 MB | 31 MB |
| Age rating | 4+ | 12+ |
| Developer | Elias Lindbergs | Roger You |
In-app purchases
QuantDojo
- Monthly$12.991 Month
- Annual$79.991 Year
- Lifetime Access$199.99
lemma
- Lemma Premium$6.997 Days
- Lemma Premium$9.991 Month
- Lemma Premium3 Days trial$59.991 Year









