# lemma: Comp Math Trainer — AMC, AIME, IMO, Putnam

> AMC, AIME, IMO, Putnam (iPhone/iPad app by Roger You.)

- Source: https://appshunter.io/ios/app/lemma-comp-math-trainer/id6770669166 (this page in markdown: same URL + `.md`)
- Developer: [Roger You](https://appshunter.io/developer/1804598101)
- Category: Education
- Price: Free with in-app purchases
- Age rating: 12+
- Requires: iOS 15.1 · 31 MB
- Languages: English
- Released: 2026-05-31
- Data updated: 2026-08-03
- User reviews in markdown: https://appshunter.io/ios/app/lemma-comp-math-trainer/id6770669166/reviews.md

## What is lemma?

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/

## Pricing and in-app purchases

Base price: Free.

**Subscriptions**

| Subscription | Price | Period |
| --- | --- | --- |
| Lemma Premium | $59.99 | per year |
| Lemma Premium | $9.99 | per month |
| Lemma Premium | $6.99 | per 7 days |



## Version history (last 2 releases)

### 1.0.1 — 2026-06-03

- fixed problem sequences in workout
- adjusted problem solution UI to be more understandable

### 1.0 — 2026-05-31

No release notes.

## More apps by Roger You

- [DareDash - Daily Social Dares](https://appshunter.io/ios/app/daredash-daily-social-dares/id6743795897)
- [rep. - simple workout tracker](https://appshunter.io/ios/app/rep-simple-workout-tracker/id6766117163)
- [bunni: women's fitness gym pal](https://appshunter.io/ios/app/bunni-womens-fitness-gym-pal/id6776007259)
- [yoked: bible accountability](https://appshunter.io/ios/app/yoked-bible-accountability/id6785301718)

All apps by Roger You: https://appshunter.io/developer/1804598101

## Related topics

[lemma](https://appshunter.io/ios/topics/lemma)

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*Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-08-03.*