# CellAtlas vs PhotoMetrix

The clearest difference is review sentiment: CellAtlas at 84% against PhotoMetrix's 67%. PhotoMetrix's advantage is update cadence (every 3 weeks vs every 2 months). 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.

CellAtlas ships an update every 2 months, PhotoMetrix every 3 weeks. The most recent releases landed on October 23, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | CellAtlas | PhotoMetrix |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[3.2 (22 ratings)](https://appshunter.io/ios/app/cellatlas/id413226907/reviews)** | — |
| Number of ratings | **22** | — |
| Positive reviews | **84.3% of reviews** | 66.7% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 2 months | **Every 3 weeks** |
| Monetization | Free | Free |
| Size | 106 MB | 27 MB |
| Requires iOS | 15.0 | 15 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [CellaVision](https://appshunter.io/developer/1185675201) | [Gilson Augusto Helfer](https://appshunter.io/developer/1131751264) |

## What reviewers say

### CellAtlas

[App page](https://appshunter.io/ios/app/cellatlas/id413226907)

Explore blood cell morphology with expert-written lectures and a vast image database. Test your knowledge with an engaging quiz game designed for efficient learning.

**Highlights:** Blood cell morphology guide, Expert-written mini lectures, Extensive cell image database, CellQuiz game, Knowledge testing

**Features:** Vision Pro support

**In-app purchases:** none

**What reviewers like**

- 👍 Great for learning morphology
- 👍 Helpful study tool
- 👍 Fun quiz format
- 👍 Easy to navigate
- 👍 Good for review

**What reviewers complain about**

- ⏰ Ridiculous timer
- ⏰ Too little time
- ⏰ Timer causes mistakes
- ⏰ Timer prevents practice
- 🐛 Quiz is broken/rigged

**Reported bugs**

- Timer is too short
- Quiz moves too slowly after correct answer
- Duplicate images that only one counts
- App not opening on some devices
- Missing WBCs

**Requested features**

- Remove timer option
- Untimed mode
- More time for quizzes
- Quizzes for specific cells/sections
- More images/examples


### PhotoMetrix

[App page](https://appshunter.io/ios/app/photometrix/id1220976347)

This application performs univariate and multivariate data analysis using image acquisition and RGB histograms. It supports various color systems and can export data and charts via email for validation with other software.

**Highlights:** Univariate analysis with Single Linear Correlation, Multivariate analysis with Principal Component Analysis (PCA), Image data acquisition via device camera, RGB histogram conversion, Support for RGB, HSV, HSL, and HSI color systems, Email export of data, analysis, and charts, Calculation of eigenvalues, eigenvectors, scores, and loadings

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

**In-app purchases:** none


## Frequently asked questions

### Is CellAtlas free?

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

### Is PhotoMetrix free?

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

### Do CellAtlas or PhotoMetrix have ads?

Neither CellAtlas nor PhotoMetrix shows ads.

### Which is updated more often, CellAtlas or PhotoMetrix?

CellAtlas ships an update every 2 months, and PhotoMetrix every 3 weeks. Most recently, CellAtlas was updated on October 23, 2026 and PhotoMetrix on October 11, 2026.

---

*Compared by [AppsHunter](https://appshunter.io/) from daily US App Store data. Review summaries are generated from verbatim App Store reviews.*