# Chempuz vs HydrogenGame

The clearest difference is price: Chempuz at Free against HydrogenGame's $2.99. HydrogenGame's advantage is in-app purchases (none vs 2) and ads (none vs shown). On device support there is nothing between them.

Chempuz is free to download; HydrogenGame costs $2.99 up front. Chempuz sells 2 one-off in-app purchases. HydrogenGame asks for nothing beyond the download.

Chempuz ships an update every 5 weeks, HydrogenGame weekly. The most recent releases landed on October 9, 2026 and October 5, 2026 respectively.

## The numbers

| Metric | Chempuz | HydrogenGame |
| --- | --- | --- |
| Price | **Free** | $2.99 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Every 5 weeks | **Weekly** |
| Monetization | Free with in-app purchases | — |
| Size | 57 MB | 89 MB |
| Requires iOS | 15.0 | **12.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [TomatoAppLab](https://appshunter.io/developer/1676711750) | [Akihiro Kakoi](https://appshunter.io/developer/1738811085) |

## What reviewers say

### Chempuz

[App page](https://appshunter.io/ios/app/chempuz/id6446211267)

Learn organic chemistry basics by creating molecules and completing puzzles. Trace functional groups to build compounds, score higher with complex structures, and use flashcards to memorize names. Enjoy learning through engaging gameplay.

**Highlights:** Create organic molecules by tracing functional groups, Build approximately 100 types of organic molecules, Score higher with more complex compound creation, Collect discovered compounds, Memorize molecule names with flashcards, Learn organic chemistry through gameplay

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| 1 gem | $0.29 | one-time |
| 10 gems | $1.99 | one-time |


### HydrogenGame

[App page](https://appshunter.io/ios/app/hydrogengame/id6480367458)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Chempuz free?

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

### Is HydrogenGame free?

HydrogenGame costs $2.99, with no in-app purchases.

### Do Chempuz or HydrogenGame have ads?

Chempuz shows ads; HydrogenGame does not.

### Which is updated more often, Chempuz or HydrogenGame?

Chempuz ships an update every 5 weeks, and HydrogenGame weekly. Most recently, Chempuz was updated on October 9, 2026 and HydrogenGame on October 5, 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.*