# Stone Identifier vs Mental Math Exercises

The clearest difference is price: Stone Identifier at Free against Mental Math Exercises's $0.29. Stone Identifier also leads on iOS requirement (12.0 vs 17.6). Mental Math Exercises's advantage is in-app purchases (none vs 5). On update cadence, ads and device support there is nothing between them.

Stone Identifier is free to download; Mental Math Exercises costs $0.29 up front. Stone Identifier sells 5 in-app purchases, starting at $4.99 per 7 days. Mental Math Exercises asks for nothing beyond the download.

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 24, 2026 and October 28, 2026 respectively.

## The numbers

| Metric | Stone Identifier | Mental Math Exercises |
| --- | --- | --- |
| Price | **Free** | $0.29 |
| Rating | **[4.9 (54 ratings)](https://appshunter.io/ios/app/stone-identifier-gemalyze/id6738392969/reviews)** | — |
| Number of ratings | **54** | — |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 2 months | Every 2 months |
| Monetization | Freemium | — |
| Size | 58 MB | 1 MB |
| Requires iOS | **12.0** | 17.6 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Picture Vision Studio LLC](https://appshunter.io/developer/1573119875) | [仁超 张](https://appshunter.io/developer/1792659119) |

## What reviewers say

### Stone Identifier

[App page](https://appshunter.io/ios/app/stone-identifier-gemalyze/id6738392969)

Instantly identify gemstones, rocks, and minerals using your camera or photo library with advanced AI. Explore detailed information, learn about birthstones, and use a magnetic sensor to detect specific materials. An AI chat assistant provides deeper insights into your discoveries.

**Highlights:** Instant AI-powered identification, Detailed rock and mineral data, Birthstone information, AI chat assistance, Magnetic sensor for detection, User-friendly interface

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

**In-app purchases (5)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Premium | $4.99 | per 7 days |
| Premium | $24.99 | per year |
| Premium | $29.99 | per year |
| Premium | $39.99 | per year |
| Premium Lifetime | $49.99 | one-time |


### Mental Math Exercises

[App page](https://appshunter.io/ios/app/mental-math-exercises/id6741766258)

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

**In-app purchases:** none


## Frequently asked questions

### Is Stone Identifier free?

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

### Is Mental Math Exercises free?

Mental Math Exercises costs $0.29, with no in-app purchases.

### Do Stone Identifier or Mental Math Exercises have ads?

Neither Stone Identifier nor Mental Math Exercises shows ads.

### Which is updated more often, Stone Identifier or Mental Math Exercises?

Stone Identifier ships an update every 2 months, and Mental Math Exercises every 2 months. Most recently, Stone Identifier was updated on October 24, 2026 and Mental Math Exercises on October 28, 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.*