# Encyclopedia vs Solar System Viewer

The clearest difference is price: Encyclopedia at Free against Solar System Viewer's $2.99. Encyclopedia also leads on update cadence (monthly vs every 2 months) and iOS requirement (15.0 vs 26.0). Solar System Viewer's advantage is rating (4.4 vs 3.8). On review sentiment, ratings volume, ads and in-app purchases there is nothing between them.

Encyclopedia is free to download; Solar System Viewer costs $2.99 up front. Encyclopedia sells 1 one-off in-app purchase and Solar System Viewer sells 4 one-off in-app purchases. Whichever you choose, the download price is not the number that matters.

Solar System Viewer holds the better App Store score, 4.4 against 3.8. Both are backed by a comparable volume of ratings — 14 and 28 respectively. Written reviews split almost evenly too, at 83% and 83% positive.

Encyclopedia ships an update monthly, Solar System Viewer every 2 months. The most recent releases landed on October 4, 2026 and October 18, 2026 respectively.

## The numbers

| Metric | Encyclopedia | Solar System Viewer |
| --- | --- | --- |
| Price | **Free** | $2.99 |
| Rating | [3.8 (14 ratings)](https://appshunter.io/ios/app/encyclopedia-solar-system/id1124568774/reviews) | **[4.4 (28 ratings)](https://appshunter.io/ios/app/solar-system-viewer-8planets/id1554639445/reviews)** |
| Number of ratings | 14 | **28** |
| Positive reviews | 83.3% of reviews | 83.3% of reviews |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | **Monthly** | Every 2 months |
| Monetization | **Free with in-app purchases** | Paid |
| Size | 322 MB | 22 MB |
| Requires iOS | **15.0** | 26.0 |
| Devices | iPhone, iPad, iPod | **iPhone, iPad, Mac, Apple Watch** |
| Age rating | 4+ | 4+ |
| Developer | [Good Spider, LLC](https://appshunter.io/developer/1487595667) | [BLUE COMET LABS LLC](https://appshunter.io/developer/1492055170) |

## What reviewers say

### Encyclopedia

[App page](https://appshunter.io/ios/app/encyclopedia-solar-system/id1124568774)

Explore the solar system with extensive articles and high-definition images. This app offers comprehensive information, engaging content, and a user-friendly interface, making it suitable for both children and adults interested in space.

**Highlights:** Thousands of articles and HD photos, Comprehensive solar system information, Engaging and easy-to-understand content, Offline availability, Badge collection for reading, Intuitive user interface

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

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Full Version | $2.99 | one-time |


### Solar System Viewer

[App page](https://appshunter.io/ios/app/solar-system-viewer-8planets/id1554639445)

Explore and simulate the orbits of planets in our solar system. This app allows you to speed up or slow down time, travel to any date, and view planetary positions. It also offers widgets for your home screen and Apple Watch complications.

**Highlights:** Simulate planetary orbits, Adjust time speed, Time travel to specific dates, Home screen widgets, Apple Watch integration, View planet overviews

**Features:** Apple Watch app, Vision Pro support

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Io Tip | $1.99 | one-time |
| Europa Tip | $3.99 | one-time |
| Ganymede Tip | $5.99 | one-time |
| Callisto Tip | $9.99 | one-time |


## Frequently asked questions

### Is Encyclopedia free?

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

### Is Solar System Viewer free?

Solar System Viewer costs $2.99, and also offers in-app purchases.

### Which has better reviews, Encyclopedia or Solar System Viewer?

Solar System Viewer is rated higher. Encyclopedia averages 3.8 out of 5 from 14 ratings, while Solar System Viewer averages 4.4 from 28 ratings.

### Do Encyclopedia or Solar System Viewer have ads?

Neither Encyclopedia nor Solar System Viewer shows ads.

### Which is updated more often, Encyclopedia or Solar System Viewer?

Encyclopedia ships an update monthly, and Solar System Viewer every 2 months. Most recently, Encyclopedia was updated on October 4, 2026 and Solar System Viewer on October 18, 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.*