# COSMOS vs Three

The clearest difference is update cadence: Three at every 5 days against COSMOS's every 2 weeks. COSMOS's advantage is ratings volume (4 vs 1). On price, rating, ads and in-app purchases there is nothing between them.

Both are free to download. COSMOS sells 3 one-off in-app purchases and Three sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

On the App Store both sit at effectively the same score — 5.0 for COSMOS against 5.0 for Three. Both are backed by a comparable volume of ratings — 4 and 1 respectively.

COSMOS ships an update every 2 weeks, Three every 5 days. The most recent releases landed on November 6, 2026 and October 31, 2026 respectively.

## The numbers

| Metric | COSMOS | Three |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [5.0 (4 ratings)](https://appshunter.io/ios/app/cosmos-3d-solar-system/id6792780408/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/three-body-simulation/id6817179834/reviews) |
| Number of ratings | **4** | 1 |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | Every 2 weeks | **Every 5 days** |
| Monetization | Free with in-app purchases | Free with in-app purchases |
| Size | 8 MB | 10 MB |
| Requires iOS | **15.0** | 16.0 |
| Devices | iPhone, iPod | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [yuudai tasaki](https://appshunter.io/developer/1861229093) | [志强 曾](https://appshunter.io/developer/1800987336) |

## What reviewers say

### COSMOS

[App page](https://appshunter.io/ios/app/cosmos-3d-solar-system/id6792780408)

Explore a real-time 3D model of the solar system with accurate planetary positions and photo-realistic textures. Control time to view past or future celestial events and learn about planets and moons. This app is free and works offline.

**Highlights:** Real-time planetary orbits, Photo-realistic textures, Time control for past/future viewing, Free and offline functionality, Detailed planet information, Exploration via pinch and swipe

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

**In-app purchases (3)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Support the Developer | $1.99 | one-time |
| Support the Developer | $4.99 | one-time |
| Support the Developer | $9.99 | one-time |


### Three

[App page](https://appshunter.io/ios/app/three-body-simulation/id6817179834)

Explore the fascinating beauty of gravity and celestial motion. Interact with three bodies, discover countless orbital paths, and experiment with your own gravity scenarios. Turn curiosity into understanding with this educational simulation.

**Highlights:** Explore 16 classic periodic solutions, Discover 10,059 3D periodic orbits, Experiment with custom gravity scenarios, Learn about the three-body problem, Offline exploration of orbits, Interactive celestial motion simulation

**Features:** Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Lifetime Unlock | $1.99 | one-time |


## Frequently asked questions

### Is COSMOS free?

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

### Is Three free?

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

### Which has better reviews, COSMOS or Three?

COSMOS and Three are both rated 5.0 out of 5 on the App Store, from 4 and 1 ratings respectively.

### Do COSMOS or Three have ads?

Neither COSMOS nor Three shows ads.

### Which is updated more often, COSMOS or Three?

COSMOS ships an update every 2 weeks, and Three every 5 days. Most recently, COSMOS was updated on November 6, 2026 and Three on October 31, 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.*