# RadioactivityCounter vs Who's in Space?

The clearest difference is price: Who's in Space? at Free against RadioactivityCounter's $4.99. Who's in Space? also leads on review sentiment (100% vs 68%) and update cadence (every 4 months vs every 15 months). RadioactivityCounter's advantage is chart position (#184 vs unranked) and ratings volume (10 vs 2). On rating, ads, in-app purchases and device support there is nothing between them.

Who's in Space? is free to download; RadioactivityCounter costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 3.1 for RadioactivityCounter against 3.0 for Who's in Space?. That said, the two scores are not equally well evidenced: RadioactivityCounter has 10 ratings behind it against 2, so its average is the more settled of the two. Written reviews are what separate them: 68% of RadioactivityCounter's written reviews are positive against 100% of Who's in Space?'s.

RadioactivityCounter ships an update every 15 months, Who's in Space? every 4 months. The most recent releases landed on November 6, 2026 and November 1, 2026 respectively.

## The numbers

| Metric | RadioactivityCounter | Who's in Space? |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Rating | **[3.1 (10 ratings)](https://appshunter.io/ios/app/radioactivitycounter/id464004677/reviews)** | [3.0 (2 ratings)](https://appshunter.io/ios/app/whos-in-space/id916499517/reviews) |
| Number of ratings | **10** | 2 |
| Positive reviews | 68.4% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 15 months | **Every 4 months** |
| Monetization | Paid | **Free** |
| Best chart rank | **#184** | — |
| Size | 11 MB | 0 MB |
| Requires iOS | **8.0** | 13.0 |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Dipl.-Ing. Rolf-Dieter Klein](https://appshunter.io/developer/309148367) | [Cameron Bernhardt](https://appshunter.io/developer/916499516) |

## What reviewers say

### RadioactivityCounter

[App page](https://appshunter.io/ios/app/radioactivitycounter/id464004677)

**Currently charting:** #184 Top Paid · Utilities (US App Store)

Transform your phone into a functional radioactivity counter. Measure gamma and some beta radiation using your device's camera sensor after calibration. Useful for personal use and experimentation with radiation sources.

**Highlights:** Real radioactivity counter functionality, Converts phone into Geiger Müller Counter, Measures gamma and some beta radiation, Requires calibration for accuracy, Expert setup for precise measurements, Supports various iPhone and iPad models

**Features:** macOS Compatibility

**In-app purchases:** none


### Who's in Space?

[App page](https://appshunter.io/ios/app/whos-in-space/id916499517)

Discover the current number of astronauts in orbit and their locations. Tap on an astronaut's name to access more detailed information about their mission.

**Highlights:** Real-time astronaut count, Astronaut location tracking, Detailed astronaut information, Data from Open Notify Astros API, User-friendly interface

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is RadioactivityCounter free?

RadioactivityCounter costs $4.99, with no in-app purchases.

### Is Who's in Space? free?

Who's in Space? is free to download, with no in-app purchases.

### Which has better reviews, RadioactivityCounter or Who's in Space??

RadioactivityCounter is rated higher. RadioactivityCounter averages 3.1 out of 5 from 10 ratings, while Who's in Space? averages 3.0 from 2 ratings.

### Do RadioactivityCounter or Who's in Space? have ads?

Neither RadioactivityCounter nor Who's in Space? shows ads.

### Which is updated more often, RadioactivityCounter or Who's in Space??

RadioactivityCounter ships an update every 15 months, and Who's in Space? every 4 months. Most recently, RadioactivityCounter was updated on November 6, 2026 and Who's in Space? on November 1, 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.*