# Rock Identifier & Gem Scanner vs Rex

The clearest difference is iOS requirement: Rock Identifier & Gem Scanner at 16.6 against Rex's 18.6. On price, ads, in-app purchases and device support there is nothing between them.

Both are free to download. Rock Identifier & Gem Scanner sells 2 in-app purchases, starting at $3.99 per 7 days and Rex sells 2 in-app purchases, starting at $12.99 per month. Whichever you choose, the download price is not the number that matters.

## The numbers

| Metric | Rock Identifier & Gem Scanner | Rex |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[5.0 (1 ratings)](https://appshunter.io/ios/app/rex-study-smarter/id6775703977/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | Yes | Yes |
| Ads | No | No |
| Update frequency | — | Weekly |
| Monetization | — | Free with in-app purchases |
| Size | 27 MB | 108 MB |
| Requires iOS | **16.6** | 18.6 |
| Devices | iPhone, iPad | **iPhone, iPad, Mac** |
| Age rating | 4+ | 12+ |
| Developer | [Mertcan Dundar Esmergul](https://appshunter.io/developer/1878026654) | [Oran Egbuchunam](https://appshunter.io/developer/6775544967) |

## What reviewers say

### Rock Identifier & Gem Scanner

[App page](https://appshunter.io/ios/app/rock-identifier-and-gem-scanner/id6760624125)

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

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro Weekly | $3.99 | per 7 days |
| Pro Annual | $39.99 | per year |


### Rex

[App page](https://appshunter.io/ios/app/rex-study-smarter/id6775703977)

This app offers an interactive learning experience by explaining concepts aloud and allowing users to manipulate 3D models and live charts. It consolidates notes, PDFs, and web research onto a single canvas and supports collaborative study sessions.

**Highlights:** Voice explanations of questions, Interactive 3D scenes and live charts, Consolidated study canvas, Lecture transcription and note-taking, Read-aloud functionality for notes and PDFs, Language practice with real scenes, Live collaborative study boards

**In-app purchases (2)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Pro | $12.99 | per month |
| Rex Pro Annual | $99.99 | per year |


## Frequently asked questions

### Is Rock Identifier & Gem Scanner free?

Rock Identifier & Gem Scanner is free to download, with in-app purchases available.

### Is Rex free?

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

### Do Rock Identifier & Gem Scanner or Rex have ads?

Neither Rock Identifier & Gem Scanner nor Rex shows ads.

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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.*