# ReactionFlash vs Gas Law Calc

The clearest difference is rating: ReactionFlash at 4.8 against Gas Law Calc's 4.2. ReactionFlash also leads on ratings volume (42 vs 5). Gas Law Calc's advantage is update cadence (weekly vs every 4 months) and review sentiment (100% vs 81%). On price, ads, in-app purchases and monetization model there is nothing between them.

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

ReactionFlash holds the better App Store score, 4.8 against 4.2. That said, the two scores are not equally well evidenced: ReactionFlash has 42 ratings behind it against 5, so its average is the more settled of the two. Written reviews complicate that: 81% of ReactionFlash's written reviews are positive against 100% of Gas Law Calc's, so the app with the better star average is not the one people write more warmly about.

ReactionFlash ships an update every 4 months, Gas Law Calc weekly. The most recent releases landed on November 10, 2026 and November 3, 2026 respectively.

## The numbers

| Metric | ReactionFlash | Gas Law Calc |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (42 ratings)](https://appshunter.io/ios/app/reactionflash/id432080813/reviews)** | [4.2 (5 ratings)](https://appshunter.io/ios/app/gas-law-calc/id6444635697/reviews) |
| Number of ratings | **42** | 5 |
| Positive reviews | 80.6% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Weekly** |
| Monetization | Free | Free |
| Size | 40 MB | 18 MB |
| Requires iOS | 15.5 | **15.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Elsevier Limited](https://appshunter.io/developer/1437273934) | [Jonathan Nakhla](https://appshunter.io/developer/1554899575) |

## 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, Vision Pro support

**In-app purchases:** none


### Gas Law Calc

[App page](https://appshunter.io/ios/app/gas-law-calc/id6444635697)

This chemistry calculator simplifies complex gas law calculations, including the ideal gas law and its variations. It also offers an element lookup with electron configuration and energy levels, plus tools for temperature, pressure, and volume conversions and dilution calculations.

**Highlights:** Ideal gas law calculations, Charles' Law and Avogadro's Law, Element lookup with electron configuration, Temperature, pressure, volume conversions, Dilution calculator

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is ReactionFlash free?

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

### Is Gas Law Calc free?

Gas Law Calc is free to download, with no in-app purchases.

### Which has better reviews, ReactionFlash or Gas Law Calc?

ReactionFlash is rated higher. ReactionFlash averages 4.8 out of 5 from 42 ratings, while Gas Law Calc averages 4.2 from 5 ratings.

### Do ReactionFlash or Gas Law Calc have ads?

Neither ReactionFlash nor Gas Law Calc shows ads.

### Which is updated more often, ReactionFlash or Gas Law Calc?

ReactionFlash ships an update every 4 months, and Gas Law Calc weekly. Most recently, ReactionFlash was updated on November 10, 2026 and Gas Law Calc 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.*