# isPrime? vs GDSII Viewer

The clearest difference is in-app purchases: isPrime? at none against GDSII Viewer's 4. isPrime? also leads on iOS requirement (15.0 vs 26.0). GDSII Viewer's advantage is update cadence (every 2 months vs every 16 months). On price, ads and device support there is nothing between them.

Both are free to download. GDSII Viewer sells 4 in-app purchases, starting at $0.99 per month. isPrime? asks for nothing beyond the download.

isPrime? ships an update every 16 months, GDSII Viewer every 2 months. Both last shipped on November 4, 2026.

## The numbers

| Metric | isPrime? | GDSII Viewer |
| --- | --- | --- |
| Price | Free | Free |
| Rating | — | **[1.0 (1 ratings)](https://appshunter.io/ios/app/gdsii-viewer/id6502424439/reviews)** |
| Number of ratings | — | **1** |
| In-app purchases | **No** | Yes |
| Ads | No | No |
| Update frequency | Every 16 months | **Every 2 months** |
| Monetization | — | Free with in-app purchases |
| Size | 4 MB | 13 MB |
| Requires iOS | **15.0** | 26.0 |
| Devices | **iPhone, iPad, iPod** | iPhone, iPad |
| Age rating | 4+ | 4+ |
| Developer | [Omer Faruk Mesebuken](https://appshunter.io/developer/1655501999) | [AIP Technology Corporation, Taiwan Branch](https://appshunter.io/developer/1733199040) |

## What reviewers say

### isPrime?

[App page](https://appshunter.io/ios/app/isprime/id6478832061)

**Features:** macOS Compatibility

**In-app purchases:** none


### GDSII Viewer

[App page](https://appshunter.io/ios/app/gdsii-viewer/id6502424439)

This utility allows users to view and analyze GDSII files, essential for semiconductor design. It offers high precision viewing, layer management, and detailed inspection tools to streamline integrated circuit design processes.

**Highlights:** High precision GDSII file viewing, Layer management and toggling, Zoom and pan functionality, Detailed inspection tools, Streamlines IC design process

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

**In-app purchases (4)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Viewer(Monthly) | $0.99 | per month |
| Viewer(Annual) | $9.99 | per year |
| Editor(Monthly) | $9.99 | per month |
| Editor(Annual) | $99.99 | per year |


## Frequently asked questions

### Is isPrime? free?

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

### Is GDSII Viewer free?

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

### Do isPrime? or GDSII Viewer have ads?

Neither isPrime? nor GDSII Viewer shows ads.

### Which is updated more often, isPrime? or GDSII Viewer?

isPrime? ships an update every 16 months, and GDSII Viewer every 2 months. Most recently, isPrime? was updated on November 4, 2026 and GDSII Viewer on November 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.*