# ReactionFlash vs Chem_Calculator

The clearest difference is rating: ReactionFlash at 4.8 against Chem_Calculator's 4.3. ReactionFlash also leads on review sentiment (81% vs 50%). Chem_Calculator's advantage is ratings volume (156 vs 42) and iOS requirement (10.0 vs 14.0). On price, update cadence, 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.

ReactionFlash holds the better App Store score, 4.8 against 4.3. Both are backed by a comparable volume of ratings — 42 and 156 respectively. Written reviews point the same way: 81% of ReactionFlash's written reviews are positive against 50% of Chem_Calculator's.

Both ship on a similar rhythm, roughly every 4 months. The most recent releases landed on October 23, 2026 and October 29, 2026 respectively.

## The numbers

| Metric | ReactionFlash | Chem_Calculator |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.8 (42 ratings)](https://appshunter.io/ios/app/reactionflash/id432080813/reviews)** | [4.3 (156 ratings)](https://appshunter.io/ios/app/chem-calculator/id1253476119/reviews) |
| Number of ratings | 42 | **156** |
| Positive reviews | **80.6% of reviews** | 50.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | Every 4 months |
| Monetization | Free | Free |
| Size | 37 MB | 34 MB |
| Requires iOS | 14.0 | **10.0** |
| Devices | iPhone, iPod | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Elsevier Limited](https://appshunter.io/developer/1437273934) | [铠宁 雷](https://appshunter.io/developer/1631727209) |

## 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


### Chem_Calculator

[App page](https://appshunter.io/ios/app/chem-calculator/id1253476119)

This app provides organic chemists with a molecular weight calculator featuring a full-sized periodic table. It allows for real-time calculation with mixed input of elements, numbers, and parentheses, and enables saving, editing, and deleting results.

**Highlights:** Molecular weight calculation, Full-sized periodic table, Real-time results, Save, edit, and delete calculations, Element detail lookup

**In-app purchases:** none


## Frequently asked questions

### Is ReactionFlash free?

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

### Is Chem_Calculator free?

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

### Which has better reviews, ReactionFlash or Chem_Calculator?

ReactionFlash is rated higher. ReactionFlash averages 4.8 out of 5 from 42 ratings, while Chem_Calculator averages 4.3 from 156 ratings.

### Do ReactionFlash or Chem_Calculator have ads?

Neither ReactionFlash nor Chem_Calculator shows ads.

### Which is updated more often, ReactionFlash or Chem_Calculator?

ReactionFlash ships an update every 4 months, and Chem_Calculator every 4 months. Most recently, ReactionFlash was updated on October 23, 2026 and Chem_Calculator on October 29, 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.*