# 자연과학OX vs PDF Grade Connect

The clearest difference is in-app purchases: PDF Grade Connect at none against 자연과학OX's 3. 자연과학OX's advantage is ads (none vs shown) and iOS requirement (15.0 vs 26.1). On price, update cadence and device support there is nothing between them.

Both are free to download. 자연과학OX sells 3 in-app purchases, starting at $2.99 per month. PDF Grade Connect asks for nothing beyond the download.

자연과학OX ships an update every 4 months, PDF Grade Connect every 3 months. The most recent releases landed on October 5, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | 자연과학OX | PDF Grade Connect |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | **No** | Yes |
| Update frequency | Every 4 months | **Every 3 months** |
| Monetization | Freemium | — |
| Size | 26 MB | 4 MB |
| Requires iOS | **15.0** | 26.1 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [CHAE HYUCK LEE](https://appshunter.io/developer/1658701307) | [Hyeonchan Yu](https://appshunter.io/developer/1857516231) |

## 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 |


### PDF Grade Connect

[App page](https://appshunter.io/ios/app/pdf-grade-connect/id6758963936)

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

**In-app purchases:** none


## Frequently asked questions

### Is 자연과학OX free?

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

### Is PDF Grade Connect free?

PDF Grade Connect is free to download, with no in-app purchases.

### Do 자연과학OX or PDF Grade Connect have ads?

PDF Grade Connect shows ads; 자연과학OX does not.

### Which is updated more often, 자연과학OX or PDF Grade Connect?

자연과학OX ships an update every 4 months, and PDF Grade Connect every 3 months. Most recently, 자연과학OX was updated on October 5, 2026 and PDF Grade Connect on October 8, 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.*