# Gradepen vs PhotoMetrix

The clearest difference is in-app purchases: PhotoMetrix at none against Gradepen's 8. PhotoMetrix also leads on review sentiment (67% vs 57%). On price, update cadence, ads and device support there is nothing between them.

Both are free to download. Gradepen sells 8 one-off in-app purchases. PhotoMetrix asks for nothing beyond the download.

Gradepen ships an update every 6 weeks, PhotoMetrix every 3 weeks. The most recent releases landed on October 19, 2026 and October 11, 2026 respectively.

## The numbers

| Metric | Gradepen | PhotoMetrix |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.5 (2 ratings)](https://appshunter.io/ios/app/gradepen/id654152733/reviews)** | — |
| Number of ratings | **2** | — |
| Positive reviews | 57.5% of reviews | **66.7% of reviews** |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 6 weeks | **Every 3 weeks** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 21 MB | 27 MB |
| Requires iOS | 15.6 | **15** |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Machlev Smart Applications Servico e Venda de Sistemas Ltda ME](https://appshunter.io/developer/654152736) | [Gilson Augusto Helfer](https://appshunter.io/developer/1131751264) |

## What reviewers say

### Gradepen

[App page](https://appshunter.io/ios/app/gradepen/id654152733)

This app automates the grading of shuffled tests using your device's camera for objective questions. Teachers can input grades for open-ended questions and export results to spreadsheets. It offers a free tier for grading assessments with up to five questions and five items.

**Highlights:** Automatic grading of objective questions, Handles shuffled question order, Input grades for open-ended questions, Export results to spreadsheet, Create and share test questions

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

**In-app purchases (8)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Plus 50 Grades Pack | $0.99 | one-time |
| Plus 150 Grades Pack | $0.99 | one-time |
| Plus 120 Grades Pack | $1.99 | one-time |
| Plus 300 Grades Pack | $1.99 | one-time |
| Plus 250 Grades Pack | $2.99 | one-time |
| Plus 600 Grades Pack | $3.99 | one-time |
| Plus 500 Grades Pack | $4.99 | one-time |
| Plus 1000 Grades Pack | $7.99 | one-time |


### 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 Gradepen free?

Gradepen is free to download, with in-app purchases available.

### Is PhotoMetrix free?

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

### Do Gradepen or PhotoMetrix have ads?

Neither Gradepen nor PhotoMetrix shows ads.

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

Gradepen ships an update every 6 weeks, and PhotoMetrix every 3 weeks. Most recently, Gradepen was updated on October 19, 2026 and PhotoMetrix on October 11, 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.*