# Tap OChem vs Crys

The clearest difference is price: Crys at Free against Tap OChem's $4.99. Crys also leads on update cadence (every 4 days vs every 3 months) and rating (5.0 vs 4.7). Tap OChem's advantage is ratings volume (39 vs 4) and iOS requirement (13.2 vs 17.0). On ads, in-app purchases and device support there is nothing between them.

Crys is free to download; Tap OChem costs $4.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Crys holds the better App Store score, 5.0 against 4.7. That said, the two scores are not equally well evidenced: Tap OChem has 39 ratings behind it against 4, so its average is the more settled of the two. Written reviews point the same way: 92% of Tap OChem's written reviews are positive against 100% of Crys's.

Tap OChem ships an update every 3 months, Crys every 4 days. The most recent releases landed on October 10, 2026 and October 7, 2026 respectively.

## The numbers

| Metric | Tap OChem | Crys |
| --- | --- | --- |
| Price | $4.99 | **Free** |
| Rating | [4.7 (39 ratings)](https://appshunter.io/ios/app/tap-ochem/id579861146/reviews) | **[5.0 (4 ratings)](https://appshunter.io/ios/app/crys-cast/id6784123301/reviews)** |
| Number of ratings | **39** | 4 |
| Positive reviews | 91.7% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 3 months | **Every 4 days** |
| Monetization | Paid | **Free** |
| Size | 3.5 GB | 8 MB |
| Requires iOS | **13.2** | 17.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Tap OChem, LLC](https://appshunter.io/developer/579861209) | [子铭 叶](https://appshunter.io/developer/6784052907) |

## What reviewers say

### Tap OChem

[App page](https://appshunter.io/ios/app/tap-ochem/id579861146)

Visualize complex organic chemistry reactions and concepts with animated explanations. This app covers a wide range of undergraduate organic chemistry topics, aiding in exam preparation and understanding of molecular behavior.

**Highlights:** Animated organic chemistry reactions, Detailed concept explanations, Electron pushing diagrams, Full-color text descriptions, MCAT, PCAT, OAT, DAT prep, Regular content updates

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

**In-app purchases:** none


### Crys

[App page](https://appshunter.io/ios/app/crys-cast/id6784123301)

This app allows users to view and analyze crystal structures locally on their mobile devices. It supports various file formats and offers tools for inspecting atoms, bonds, and unit cells, with features for generating simulated PXRD patterns and morphology previews.

**Highlights:** Local structure viewing, Supports CIF, XYZ, PDB, MOL, SDF, MOL2, RES files, Inspect atoms, bonds, unit cells, Display styles and scope control, Fullscreen and PXRD presentation modes, Simulated PXRD pattern generation, BFDH morphology preview

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

**In-app purchases:** none


## Frequently asked questions

### Is Tap OChem free?

Tap OChem costs $4.99, with no in-app purchases.

### Is Crys free?

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

### Which has better reviews, Tap OChem or Crys?

Crys is rated higher. Tap OChem averages 4.7 out of 5 from 39 ratings, while Crys averages 5.0 from 4 ratings.

### Do Tap OChem or Crys have ads?

Neither Tap OChem nor Crys shows ads.

### Which is updated more often, Tap OChem or Crys?

Tap OChem ships an update every 3 months, and Crys every 4 days. Most recently, Tap OChem was updated on October 10, 2026 and Crys on October 7, 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.*