# III vs 磐石

The clearest difference is price: 磐石 at Free against III's $2.99. 磐石 also leads on rating (5.0 vs 4.0). On review sentiment, ratings volume, update cadence and ads there is nothing between them.

磐石 is free to download; III costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

磐石 holds the better App Store score, 5.0 against 4.0. Both are backed by a comparable volume of ratings — 1 and 1 respectively. Written reviews split almost evenly too, at 100% and 100% positive.

III ships an update every 17 months, 磐石 every 9 months. The most recent releases landed on August 24, 2026 and June 4, 2026 respectively.

## The numbers

| Metric | III | 磐石 |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | [4.0 (1 ratings)](https://appshunter.io/ios/app/iii-v-comp/id475184953/reviews) | **[5.0 (1 ratings)](https://appshunter.io/ios/app/id1579805721/reviews)** |
| Number of ratings | 1 | 1 |
| Positive reviews | 100.0% of reviews | 100.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 17 months | **Every 9 months** |
| Monetization | Paid | **Free** |
| Size | 10 MB | 32 MB |
| Requires iOS | **11.0** | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 17+ |
| Developer | [Takuya Ishikawa](https://appshunter.io/developer/468311118) | [上海基文文化传播有限公司](https://appshunter.io/developer/1552318592) |

## What reviewers say

### III

[App page](https://appshunter.io/ios/app/iii-v-comp/id475184953)

Calculate material properties for III-V compound semiconductors like AlGaInAsP. It determines compositions, lattice constant, strain, bandgap, and effective masses for InP or GaAs substrates.

**Highlights:** III-V compound semiconductor calculations, Material property determination, Composition calculation (x, y, z), Lattice constant and strain analysis, Bandgap and effective mass calculation, Supports InP and GaAs substrates

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

**In-app purchases:** none


### 磐石

[App page](https://appshunter.io/ios/app/id1579805721)

This app provides rich spiritual and devotional content to help users build their faith on a solid foundation. It offers a curated experience for personal spiritual growth and reflection.

**Highlights:** Spiritual devotionals, Faith building content, Personal spiritual growth, Reflection tools

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is III free?

III costs $2.99, with no in-app purchases.

### Is 磐石 free?

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

### Which has better reviews, III or 磐石?

磐石 is rated higher. III averages 4.0 out of 5 from 1 ratings, while 磐石 averages 5.0 from 1 ratings.

### Do III or 磐石 have ads?

Neither III nor 磐石 shows ads.

### Which is updated more often, III or 磐石?

III ships an update every 17 months, and 磐石 every 9 months. Most recently, III was updated on August 24, 2026 and 磐石 on June 4, 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.*