# Isotope Browser vs Decay Tree

The clearest difference is rating: Isotope Browser at 4.8 against Decay Tree's 4.1. Isotope Browser also leads on in-app purchases (none vs 2) and ads (none vs shown). Decay Tree's advantage is review sentiment (100% vs 83%). On price, device support and iOS requirement there is nothing between them.

Both are free to download. Decay Tree sells 2 one-off in-app purchases. Isotope Browser asks for nothing beyond the download.

Isotope Browser holds the better App Store score, 4.8 against 4.1. Both are backed by a comparable volume of ratings — 27 and 7 respectively. Written reviews complicate that: 83% of Isotope Browser's written reviews are positive against 100% of Decay Tree's, so the app with the better star average is not the one people write more warmly about.

Isotope Browser ships an update every 6 weeks, Decay Tree every 11 months. The most recent releases landed on October 16, 2026 and October 13, 2026 respectively.

## The numbers

| Metric | Isotope Browser | Decay Tree |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (27 ratings)](https://appshunter.io/ios/app/isotope-browser/id943890538/reviews)** | [4.1 (7 ratings)](https://appshunter.io/ios/app/decay-tree/id1066023546/reviews) |
| Number of ratings | **27** | 7 |
| Positive reviews | 82.6% of reviews | **100.0% of reviews** |
| In-app purchases | **No** | Yes |
| Ads | **No** | Yes |
| Update frequency | **Every 6 weeks** | Every 11 months |
| Monetization | **Free** | Free with in-app purchases |
| Size | 8 MB | 53 MB |
| Requires iOS | **11.0** | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [IAEA](https://appshunter.io/developer/535500126) | [Gustaf Holst](https://appshunter.io/developer/1066023545) |

## 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


### Decay Tree

[App page](https://appshunter.io/ios/app/decay-tree/id1066023546)

This educational app visually represents nuclear decay chains for various nuclides. It graphically displays decay modes and half-lives, alongside detailed tables and graphs of spin, specific activity, and emitted particles.

**Highlights:** Visualizes decay chains, Graphical display of decay modes, Graphical display of half-lives, Tabulated details of spin, specific activity, emitted particles, Graphs of spin, specific activity, emitted particles

**Features:** macOS Compatibility

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Radiation Table | $0.99 | one-time |
| Remove Ads | $1.99 | one-time |


## Frequently asked questions

### Is Isotope Browser free?

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

### Is Decay Tree free?

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

### Which has better reviews, Isotope Browser or Decay Tree?

Isotope Browser is rated higher. Isotope Browser averages 4.8 out of 5 from 27 ratings, while Decay Tree averages 4.1 from 7 ratings.

### Do Isotope Browser or Decay Tree have ads?

Decay Tree shows ads; Isotope Browser does not.

### Which is updated more often, Isotope Browser or Decay Tree?

Isotope Browser ships an update every 6 weeks, and Decay Tree every 11 months. Most recently, Isotope Browser was updated on October 16, 2026 and Decay Tree on October 13, 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.*