# Mars Book vs Mars Terraforming Project

The clearest difference is in-app purchases: Mars Book at none against Mars Terraforming Project's 2. Mars Book also leads on iOS requirement (9.0 vs 12.0). Mars Terraforming Project's advantage is update cadence (daily vs every 13 months). On price, ads and device support there is nothing between them.

Both are free to download. Mars Terraforming Project sells 2 in-app purchases, starting at $4.99 per month. Mars Book asks for nothing beyond the download.

Mars Book ships an update every 13 months, Mars Terraforming Project daily. The most recent releases landed on October 13, 2026 and October 24, 2026 respectively.

## The numbers

| Metric | Mars Book | Mars Terraforming Project |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[4.6 (5 ratings)](https://appshunter.io/ios/app/mars-terraforming-project/id6738961017/reviews)** |
| Number of ratings | — | **5** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 13 months | **Daily** |
| Monetization | — | Freemium |
| Size | 14 MB | 42 MB |
| Requires iOS | **9.0** | 12.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Vixen Co.,Ltd.](https://appshunter.io/developer/536188843) | [Madhanrajan Varadharajan](https://appshunter.io/developer/1047714662) |

## What reviewers say

### Mars Book

[App page](https://appshunter.io/ios/app/mars-book/id1342509724)

**In-app purchases:** none


### Mars Terraforming Project

[App page](https://appshunter.io/ios/app/mars-terraforming-project/id6738961017)

Explore the science and engineering behind colonizing Mars. Engage in AI-driven narrative adventures that adapt to your choices, offering a unique way to learn about transforming the Red Planet into a habitable world.

**Highlights:** A-Z step-by-step terraforming tutorials, AI-generated D&D style Mars games, Customizable AI game prompts and actions, Educational content on science and engineering, Narrative-driven space adventures

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Unlock Pro Monthly | $4.99 | per month |
| Unlock the annual pro access | $19.99 | per year |


## Frequently asked questions

### Is Mars Book free?

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

### Is Mars Terraforming Project free?

Mars Terraforming Project is free to download, with in-app purchases available.

### Do Mars Book or Mars Terraforming Project have ads?

Neither Mars Book nor Mars Terraforming Project shows ads.

### Which is updated more often, Mars Book or Mars Terraforming Project?

Mars Book ships an update every 13 months, and Mars Terraforming Project daily. Most recently, Mars Book was updated on October 13, 2026 and Mars Terraforming Project on October 24, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*