# 化学の王様 vs OSU

The clearest difference is in-app purchases: OSU at none against 化学の王様's 3. OSU also leads on ads (none vs shown) and iOS requirement (13.0 vs 15.0). 化学の王様's advantage is update cadence (every 3 weeks vs every 7 months). On price and device support there is nothing between them.

Both are free to download. 化学の王様 sells 3 in-app purchases, starting at $3.49 per month. OSU asks for nothing beyond the download.

化学の王様 ships an update every 3 weeks, OSU every 7 months. The most recent releases landed on November 7, 2026 and November 8, 2026 respectively.

## The numbers

| Metric | 化学の王様 | OSU |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[5.0 (3 ratings)](https://appshunter.io/ios/app/id1519715518/reviews)** | — |
| Number of ratings | **3** | — |
| Positive reviews | 42.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | **Every 3 weeks** | Every 7 months |
| Monetization | Free with in-app purchases | — |
| Size | 139 MB | 31 MB |
| Requires iOS | 15.0 | **13.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [HANAUTA INC.](https://appshunter.io/developer/492009717) | [eita nakagaichi](https://appshunter.io/developer/1814037621) |

## What reviewers say

### 化学の王様

[App page](https://appshunter.io/ios/app/id1519715518)

This app offers a fun, quiz-like approach to learning high school chemistry. It features over 3000 questions in various formats and is designed to help users memorize key concepts for exams. Users can progress through stages and earn rewards while studying.

**Highlights:** Over 3000 chemistry questions, Quiz-like learning format, Short play sessions, Exam preparation content, Game-like progression, Gift rewards for quests

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 合格プラン | $3.49 | per month |
| 合格プラン | $17.49 | per 6 months |
| 合格プラン | $27.99 | per year |


### OSU

[App page](https://appshunter.io/ios/app/osu-ds/id6745809127)

**In-app purchases:** none


## Frequently asked questions

### Is 化学の王様 free?

化学の王様 is free to download, with in-app purchases available.

### Is OSU free?

OSU is free to download, with no in-app purchases.

### Do 化学の王様 or OSU have ads?

化学の王様 shows ads; OSU does not.

### Which is updated more often, 化学の王様 or OSU?

化学の王様 ships an update every 3 weeks, and OSU every 7 months. Most recently, 化学の王様 was updated on November 7, 2026 and OSU on November 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.*