# Codon One vs Charm24

The clearest difference is in-app purchases: Charm24 at none against Codon One's 7. Charm24 also leads on update cadence (every 2 days vs every 3 weeks). Codon One's advantage is device support (3 vs 1) and iOS requirement (15.6 vs 26.2). On price and ads there is nothing between them.

Both are free to download. Codon One sells 7 one-off in-app purchases. Charm24 asks for nothing beyond the download.

Codon One ships an update every 3 weeks, Charm24 every 2 days. The most recent releases landed on October 24, 2026 and October 8, 2026 respectively.

## The numbers

| Metric | Codon One | Charm24 |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (24 ratings)](https://appshunter.io/ios/app/codon-one-biology-study/id1517313390/reviews)** | — |
| Number of ratings | **24** | — |
| Positive reviews | 76.5% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 3 weeks | **Every 2 days** |
| Monetization | Free with in-app purchases | — |
| Size | 277 MB | 3 MB |
| Requires iOS | **15.6** | 26.2 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Daniel Gebert](https://appshunter.io/developer/1517313389) | [JT Scientific Consulting LLC](https://appshunter.io/developer/1612699648) |

## What reviewers say

### Codon One

[App page](https://appshunter.io/ios/app/codon-one-biology-study/id1517313390)

Master molecular biology, genetics, evolution, and life chemistry through interactive modules and quizzes. Explore essential concepts with clear diagrams and concise explanations. Includes helpful tools for sequence analysis and genetic code reference.

**Highlights:** Interactive learning modules, Quick quizzes for comprehension, Clear diagrams and plain language, Molecule reference guide, Sequence analysis tools, Genetic code exploration

**Features:** Family Sharing, Vision Pro support

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Module 1: Chemistry of Life | Free | one-time |
| Module 2: Genetics | $2.99 | one-time |
| Module 3: Evolution | $2.99 | one-time |
| Module 4: Science History | $2.99 | one-time |
| Module 5: Cell Biology | $2.99 | one-time |
| Module 6: Development | $2.99 | one-time |
| Unlock All | $8.99 | one-time |


### Charm24

[App page](https://appshunter.io/ios/app/charm24/id6759074996)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Codon One free?

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

### Is Charm24 free?

Charm24 is free to download, with no in-app purchases.

### Do Codon One or Charm24 have ads?

Neither Codon One nor Charm24 shows ads.

### Which is updated more often, Codon One or Charm24?

Codon One ships an update every 3 weeks, and Charm24 every 2 days. Most recently, Codon One was updated on October 24, 2026 and Charm24 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.*