# lemma vs Estimation & Decision Game PRO

The clearest difference is price: lemma at Free against Estimation & Decision Game PRO's $1.99. lemma also leads on iOS requirement (15.1 vs 17.0). Estimation & Decision Game PRO's advantage is update cadence (daily vs every 3 days). On ads, in-app purchases and device support there is nothing between them.

lemma is free to download; Estimation & Decision Game PRO costs $1.99 up front. lemma sells 3 in-app purchases, starting at $6.99 per 7 days and Estimation & Decision Game PRO sells 3 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

lemma ships an update every 3 days, Estimation & Decision Game PRO daily. The most recent releases landed on September 19, 2026 and September 17, 2026 respectively.

## The numbers

| Metric | lemma | Estimation & Decision Game PRO |
| --- | --- | --- |
| Price | **Free** | $1.99 |
| Rating | **[5.0 (1 ratings)](https://appshunter.io/ios/app/lemma-comp-math-trainer/id6770669166/reviews)** | — |
| Number of ratings | **1** | — |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 3 days | **Daily** |
| Monetization | Free with in-app purchases | — |
| Size | 31 MB | 4 MB |
| Requires iOS | **15.1** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 12+ | 4+ |
| Developer | [Roger You](https://appshunter.io/developer/1804598101) | [Aneesh Pradeep](https://appshunter.io/developer/1836157821) |

## What reviewers say

### lemma

[App page](https://appshunter.io/ios/app/lemma-comp-math-trainer/id6770669166)

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.

**Highlights:** Daily timed problem sprints, Per-category ELO skill tracking, Adaptive difficulty, Hints and step-through solutions, Streaks, XP, and achievements, Leaderboard

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Lemma Premium | $6.99 | per 7 days |
| Lemma Premium | $9.99 | per month |
| Lemma Premium | $59.99 | per year |


### Estimation & Decision Game PRO

[App page](https://appshunter.io/ios/app/estimation-and-decision-game-pro/id6787817317)

**Features:** macOS Compatibility, Vision Pro support

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 Deep Dive | $2.99 | one-time |
| 3 Deep Dives | $6.99 | one-time |
| 10 Deep Dives | $19.99 | one-time |


## Frequently asked questions

### Is lemma free?

lemma is free to download, with in-app purchases available.

### Is Estimation & Decision Game PRO free?

Estimation & Decision Game PRO costs $1.99, and also offers in-app purchases.

### Do lemma or Estimation & Decision Game PRO have ads?

Neither lemma nor Estimation & Decision Game PRO shows ads.

### Which is updated more often, lemma or Estimation & Decision Game PRO?

lemma ships an update every 3 days, and Estimation & Decision Game PRO daily. Most recently, lemma was updated on September 19, 2026 and Estimation & Decision Game PRO on September 17, 2026.

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*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*