# 자연과학OX vs StatRedPen

The clearest difference is ads: 자연과학OX at none against StatRedPen's shown. 자연과학OX also leads on device support (3 vs 1) and iOS requirement (15.0 vs 17.0). StatRedPen's advantage is update cadence (every 2 days vs every 4 months). On price and in-app purchases there is nothing between them.

Both are free to download. 자연과학OX sells 3 in-app purchases, starting at $2.99 per month and StatRedPen sells 2 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

자연과학OX ships an update every 4 months, StatRedPen every 2 days. The most recent releases landed on October 5, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | 자연과학OX | StatRedPen |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | Yes |
| Ads | **No** | Yes |
| Update frequency | Every 4 months | **Every 2 days** |
| Monetization | Freemium | — |
| Size | 26 MB | 5 MB |
| Requires iOS | **15.0** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [CHAE HYUCK LEE](https://appshunter.io/developer/1658701307) | [丽佳 施](https://appshunter.io/developer/1894580777) |

## What reviewers say

### 자연과학OX

[App page](https://appshunter.io/ios/app/ox/id6479007396)

This app offers practice quizzes for recent natural science topics, covering physics, chemistry, biology, and earth science. It provides subscription options for enhanced learning features and detailed explanations.

**Highlights:** Physics quizzes, Chemistry quizzes, Biology quizzes, Earth science quizzes, Subscription for explanations, Practice quizzes

**Features:** macOS Compatibility

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 단원 설정권 | $2.99 | per month |
| 무제한 해설권 | $3.99 | per month |
| 평생 자유 이용권 | $19.99 | one-time |


### StatRedPen

[App page](https://appshunter.io/ios/app/statredpen-stats-exam-grader/id6794589846)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 완전판 해금 | $0.99 | one-time |
| Remove Ads | $0.99 | one-time |


## Frequently asked questions

### Is 자연과학OX free?

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

### Is StatRedPen free?

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

### Do 자연과학OX or StatRedPen have ads?

StatRedPen shows ads; 자연과학OX does not.

### Which is updated more often, 자연과학OX or StatRedPen?

자연과학OX ships an update every 4 months, and StatRedPen every 2 days. Most recently, 자연과학OX was updated on October 5, 2026 and StatRedPen on October 21, 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.*