# Solar Book vs Intergalactic Solar System

The clearest difference is rating: Solar Book at 4.7 against Intergalactic Solar System's 4.0. Solar Book also leads on in-app purchases (none vs 1). Intergalactic Solar System's advantage is update cadence (monthly vs every 14 months) and ratings volume (25 vs 3). On price, ads, device support and iOS requirement there is nothing between them.

Both are free to download. Intergalactic Solar System sells 1 one-off in-app purchase. Solar Book asks for nothing beyond the download.

Solar Book holds the better App Store score, 4.7 against 4.0. That said, the two scores are not equally well evidenced: Intergalactic Solar System has 25 ratings behind it against 3, so its average is the more settled of the two.

Solar Book ships an update every 14 months, Intergalactic Solar System monthly. The most recent releases landed on October 19, 2026 and October 9, 2026 respectively.

## The numbers

| Metric | Solar Book | Intergalactic Solar System |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.7 (3 ratings)](https://appshunter.io/ios/app/solar-book/id1078873201/reviews)** | [4.0 (25 ratings)](https://appshunter.io/ios/app/intergalactic-solar-system/id1505399254/reviews) |
| Number of ratings | 3 | **25** |
| Positive reviews | — | 70.0% of reviews |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 14 months | **Monthly** |
| Monetization | **Free** | Free with in-app purchases |
| Size | 5 MB | 355 MB |
| Requires iOS | **12.0** | 13.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Vixen Co.,Ltd.](https://appshunter.io/developer/536188843) | [Intergalactic Education LLC](https://appshunter.io/developer/1364648815) |

## What reviewers say

### Solar Book

[App page](https://appshunter.io/ios/app/solar-book/id1078873201)

This app provides detailed information about solar eclipses, including timings for different phases based on your location. It allows you to view sequential images and star charts for planning and observation.

**Highlights:** Solar eclipse phase timing, Location-based eclipse calculations, Sequential eclipse image display, Star chart visualization, Past and future eclipse planning

**In-app purchases:** none


### Intergalactic Solar System

[App page](https://appshunter.io/ios/app/intergalactic-solar-system/id1505399254)

Explore planets, moons, and countries in this space simulator mini-game. Learn astronomy and geography aligned with next-generation science standards. Discover the Milky Way galaxy and assess your knowledge through engaging gameplay.

**Highlights:** Planet and moon exploration, Country geography learning, Milky Way galaxy view, Common Core aligned curriculum, Proficiency assessment, Engaging gameplay levels

**Features:** macOS Compatibility

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Access to Full Game | $3.99 | one-time |


## Frequently asked questions

### Is Solar Book free?

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

### Is Intergalactic Solar System free?

Intergalactic Solar System is free to download, with in-app purchases available.

### Which has better reviews, Solar Book or Intergalactic Solar System?

Solar Book is rated higher. Solar Book averages 4.7 out of 5 from 3 ratings, while Intergalactic Solar System averages 4.0 from 25 ratings.

### Do Solar Book or Intergalactic Solar System have ads?

Neither Solar Book nor Intergalactic Solar System shows ads.

### Which is updated more often, Solar Book or Intergalactic Solar System?

Solar Book ships an update every 14 months, and Intergalactic Solar System monthly. Most recently, Solar Book was updated on October 19, 2026 and Intergalactic Solar System on October 9, 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.*