# Isotope Browser vs Space Time Quest

The clearest difference is ratings volume: Isotope Browser at 27 against Space Time Quest's 1. Isotope Browser also leads on update cadence (every 6 weeks vs every 4 months). Space Time Quest's advantage is iOS requirement (8.0 vs 11.0). On price, rating, ads and in-app purchases there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

Space Time Quest holds the better App Store score, 5.0 against 4.8. That said, the two scores are not equally well evidenced: Isotope Browser has 27 ratings behind it against 1, so its average is the more settled of the two.

Isotope Browser ships an update every 6 weeks, Space Time Quest every 4 months. The most recent releases landed on November 1, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | Isotope Browser | Space Time Quest |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (27 ratings)](https://appshunter.io/ios/app/isotope-browser/id943890538/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/space-time-quest/id1282496629/reviews)** |
| Number of ratings | **27** | 1 |
| Positive reviews | 82.6% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 6 weeks** | Every 4 months |
| Monetization | Free | Free |
| Size | 8 MB | 161 MB |
| Requires iOS | 11.0 | **8.0** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [IAEA](https://appshunter.io/developer/535500126) | [Laser Labs](https://appshunter.io/developer/1076013854) |

## What reviewers say

### Isotope Browser

[App page](https://appshunter.io/ios/app/isotope-browser/id943890538)

Access comprehensive nuclear data for over 4,000 nuclides and isomers. Explore interactive charts, filter by various criteria, and view detailed information for each nuclide. Data is sourced from reliable resources and available offline.

**Highlights:** Properties of over 4,000 nuclides and isomers, Interactive Chart of Nuclides, Periodic Table of Elements, Filter by half-life, decay mode, radiation type, and energy, Detailed nuclide information with web links, Offline access to embedded database

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

**In-app purchases:** none


### Space Time Quest

[App page](https://appshunter.io/ios/app/space-time-quest/id1282496629)

Manage a massive budget and lead a continent-spanning scientific project to build a gravitational wave detector. Optimize subsystems and be the first to discover elusive gravitational waves to win a Nobel Prize.

**Highlights:** Budget management, Scientific project simulation, Gravitational wave detector construction, Subsystem optimization, Discovery simulation, Multilingual support

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is Isotope Browser free?

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

### Is Space Time Quest free?

Space Time Quest is free to download, with no in-app purchases.

### Which has better reviews, Isotope Browser or Space Time Quest?

Space Time Quest is rated higher. Isotope Browser averages 4.8 out of 5 from 27 ratings, while Space Time Quest averages 5.0 from 1 ratings.

### Do Isotope Browser or Space Time Quest have ads?

Neither Isotope Browser nor Space Time Quest shows ads.

### Which is updated more often, Isotope Browser or Space Time Quest?

Isotope Browser ships an update every 6 weeks, and Space Time Quest every 4 months. Most recently, Isotope Browser was updated on November 1, 2026 and Space Time Quest on November 3, 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.*