# iStellar vs Koudo

The clearest difference is update cadence: Koudo at every 5 days against iStellar's every 3 months. On ads, in-app purchases, device support and iOS requirement there is nothing between them.

iStellar ships an update every 3 months, Koudo every 5 days. The most recent releases landed on September 27, 2026 and August 23, 2026 respectively.

## The numbers

| Metric | iStellar | Koudo |
| --- | --- | --- |
| Price | **$3.99** | — |
| Rating | **[4.0 (1 ratings)](https://appshunter.io/ios/app/istellar/id293118835/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | 49.3% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 5 days** |
| Monetization | Paid | — |
| Size | 37 MB | 25 MB |
| Requires iOS | **12.4** | 13.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [AstroArts Inc.](https://appshunter.io/developer/293118838) | [Hajime Kato](https://appshunter.io/developer/6779136342) |

## What reviewers say

### iStellar

[App page](https://appshunter.io/ios/app/istellar/id293118835)

Explore the cosmos with a realistic planetarium experience. View the night sky from any location and time, with detailed celestial bodies and dynamic simulations. Intuitive multi-touch controls make navigation effortless.

**Highlights:** Real-time starry sky simulation, Adjustable location and time, Detailed celestial object data, Intuitive multi-touch controls, Solar eclipse simulation, Object search function

**Features:** Vision Pro support

**In-app purchases:** none


### Koudo

[App page](https://appshunter.io/ios/app/koudo/id6779136340)

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

**In-app purchases:** none


## Frequently asked questions

### Is iStellar free?

iStellar costs $3.99, with no in-app purchases.

### Is Koudo free?

Pricing for Koudo is not currently listed on the App Store.

### Do iStellar or Koudo have ads?

Neither iStellar nor Koudo shows ads.

### Which is updated more often, iStellar or Koudo?

iStellar ships an update every 3 months, and Koudo every 5 days. Most recently, iStellar was updated on September 27, 2026 and Koudo on August 23, 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.*