# ISS Detector vs PYX

The clearest difference is in-app purchases: PYX at none against ISS Detector's 9. PYX also leads on ads (none vs shown) and update cadence (every 9 days vs monthly). On price, device support and iOS requirement there is nothing between them.

Both are free to download. ISS Detector sells 7 in-app purchases, starting at $0.99 per month. PYX asks for nothing beyond the download.

ISS Detector ships an update monthly, PYX every 9 days. The most recent releases landed on November 2, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | ISS Detector | PYX |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.6 (729 ratings)](https://appshunter.io/ios/app/iss-detector/id1198597805/reviews)** | — |
| Number of ratings | **729** | — |
| Positive reviews | 55.4% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | Yes | **No** |
| Update frequency | Monthly | **Every 9 days** |
| Monetization | Free with in-app purchases | — |
| Size | 33 MB | 256 MB |
| Requires iOS | 16.0 | **15.0** |
| Devices | iPhone, iPad | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Derk Vrijdag](https://appshunter.io/developer/1198597804) | [Aix Marseille Université](https://appshunter.io/developer/1449701057) |

## What reviewers say

### ISS Detector

[App page](https://appshunter.io/ios/app/iss-detector/id1198597805)

Easily track the International Space Station and other satellites. Receive timely alarms before passes and get weather condition checks for optimal viewing. Enhance functionality with optional in-app purchases to discover more celestial objects.

**Highlights:** ISS tracking and alerts, Weather condition checks, Alarm notifications, Track Starlink trains, Track Hubble telescope, Track amateur radio satellites

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

**In-app purchases (7)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium Access | $0.99 | per month |
| Donation | $1.99 | per month |
| Premium Access | $1.99 | per month |
| Premium Access | $2.99 | per year |
| Premium Access | $5.99 | per year |
| Donation | $5.99 | per year |
| Premium Access | $11.99 | per year |


### PYX

[App page](https://appshunter.io/ios/app/pyx/id6756005957)

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is ISS Detector free?

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

### Is PYX free?

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

### Do ISS Detector or PYX have ads?

ISS Detector shows ads; PYX does not.

### Which is updated more often, ISS Detector or PYX?

ISS Detector ships an update monthly, and PYX every 9 days. Most recently, ISS Detector was updated on November 2, 2026 and PYX on October 25, 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.*