# ReactionFlash vs Isotope Browser

The clearest difference is update cadence: Isotope Browser at every 6 weeks against ReactionFlash's every 4 months. Isotope Browser also leads on iOS requirement (11.0 vs 14.0). On price, rating, review sentiment and ratings volume there is nothing between them.

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

On the App Store both sit at effectively the same score — 4.8 for ReactionFlash against 4.8 for Isotope Browser. Both are backed by a comparable volume of ratings — 41 and 27 respectively. Written reviews are what separate them: 81% of ReactionFlash's written reviews are positive against 83% of Isotope Browser's.

ReactionFlash ships an update every 4 months, Isotope Browser every 6 weeks. Both last shipped on September 21, 2026.

## The numbers

| Metric | ReactionFlash | Isotope Browser |
| --- | --- | --- |
| Price | Free | Free |
| Rating | [4.8 (41 ratings)](https://appshunter.io/ios/app/reactionflash/id432080813/reviews) | [4.8 (27 ratings)](https://appshunter.io/ios/app/isotope-browser/id943890538/reviews) |
| Number of ratings | **41** | 27 |
| Positive reviews | 80.6% of reviews | **82.6% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 6 weeks** |
| Monetization | Free | Free |
| Size | 37 MB | 8 MB |
| Requires iOS | 14.0 | **11.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Elsevier Limited](https://appshunter.io/developer/1437273934) | [IAEA](https://appshunter.io/developer/535500126) |

## What reviewers say

### ReactionFlash

[App page](https://appshunter.io/ios/app/reactionflash/id432080813)

This app serves as a comprehensive flashcard-style learning tool for named chemical reactions. It provides detailed information on reaction mechanisms and examples from scientific literature, with a quiz mode to test user knowledge.

**Highlights:** Learn named chemical reactions, Understand reaction mechanisms, View literature examples, Quiz mode for knowledge testing, Flashcard interface

**Features:** macOS Compatibility

**In-app purchases:** none


### 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


## Frequently asked questions

### Is ReactionFlash free?

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

### Is Isotope Browser free?

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

### Which has better reviews, ReactionFlash or Isotope Browser?

ReactionFlash and Isotope Browser are both rated 4.8 out of 5 on the App Store, from 41 and 27 ratings respectively.

### Do ReactionFlash or Isotope Browser have ads?

Neither ReactionFlash nor Isotope Browser shows ads.

### Which is updated more often, ReactionFlash or Isotope Browser?

ReactionFlash ships an update every 4 months, and Isotope Browser every 6 weeks. Most recently, ReactionFlash was updated on September 21, 2026 and Isotope Browser on September 21, 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.*