# III vs STEPPASS（ステップパス）

The clearest difference is review sentiment: III at 100% against STEPPASS（ステップパス）'s 25%. STEPPASS（ステップパス）'s advantage is price (Free vs $2.99). On update cadence, ads, in-app purchases and device support there is nothing between them.

STEPPASS（ステップパス） is free to download; III costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

III ships an update every 17 months, STEPPASS（ステップパス） every 15 months. The most recent releases landed on August 24, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | III | STEPPASS（ステップパス） |
| --- | --- | --- |
| Price | $2.99 | **Free** |
| Rating | **[4.0 (1 ratings)](https://appshunter.io/ios/app/iii-v-comp/id475184953/reviews)** | — |
| Number of ratings | **1** | — |
| Positive reviews | **100.0% of reviews** | 25.0% of reviews |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 17 months | **Every 15 months** |
| Monetization | Paid | **Free** |
| Size | 10 MB | 12 MB |
| Requires iOS | **11.0** | 12.0 |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Takuya Ishikawa](https://appshunter.io/developer/468311118) | [STEP CO., LTD. (Kanagawa)](https://appshunter.io/developer/1509836521) |

## 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


### STEPPASS（ステップパス）

[App page](https://appshunter.io/ios/app/steppass/id1509836522)

This app delivers important messages and notifications directly to your smartphone. It ensures you never miss crucial updates from your learning center through push notifications.

**Highlights:** Receive messages on smartphone, Push notification alerts, Prevent missed messages, Exclusive for STEP students

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is III free?

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

### Is STEPPASS（ステップパス） free?

STEPPASS（ステップパス） is free to download, with no in-app purchases.

### Do III or STEPPASS（ステップパス） have ads?

Neither III nor STEPPASS（ステップパス） shows ads.

### Which is updated more often, III or STEPPASS（ステップパス）?

III ships an update every 17 months, and STEPPASS（ステップパス） every 15 months. Most recently, III was updated on August 24, 2026 and STEPPASS（ステップパス） on September 21, 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.*