# SSG On Site vs Stack Testers Friend

The clearest difference is review sentiment: Stack Testers Friend at 100% against SSG On Site's 50%. Stack Testers Friend also leads on device support (3 vs 1) and iOS requirement (13.0 vs 16.6). SSG On Site's advantage is update cadence (every 10 days vs every 7 months). On price, ads, in-app purchases and monetization model there is nothing between them.

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

SSG On Site ships an update every 10 days, Stack Testers Friend every 7 months. The most recent releases landed on October 17, 2026 and September 24, 2026 respectively.

## The numbers

| Metric | SSG On Site | Stack Testers Friend |
| --- | --- | --- |
| Price | Free | Free |
| Positive reviews | 50.0% of reviews | **100.0% of reviews** |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 10 days** | Every 7 months |
| Monetization | Free | Free |
| Size | 109 MB | 33 MB |
| Requires iOS | 16.6 | **13.0** |
| Devices | iPhone | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [SSG Standard Solutions Group AB](https://appshunter.io/developer/1344709576) | [Lewis Holmes](https://appshunter.io/developer/1454834389) |

## What reviewers say

### SSG On Site

[App page](https://appshunter.io/ios/app/ssg-on-site/id1287924689)

Access crucial worksite information, including safety guidelines, contact details, and maps. Stay informed with the latest news and report accidents directly from your mobile device.

**Highlights:** Safety instructions, Contact details, Maps, Latest news updates, Accident alerts

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

**In-app purchases:** none


### Stack Testers Friend

[App page](https://appshunter.io/ios/app/stack-testers-friend/id1454834390)

This mobile toolkit provides essential on-site calculations for stack testers. Quickly perform gas conversions, probe position calculations, and other vital engineering tasks without needing a laptop. It's designed for environmental engineers needing immediate access to data while working in the field.

**Highlights:** Gas conversion calculations, Isokinetic sample position calculations, Extraction rate calculations, Gas density calculations, Particulate matter normalization, Calibration function calculations

**Features:** macOS Compatibility

**In-app purchases:** none


## Frequently asked questions

### Is SSG On Site free?

SSG On Site is free to download, with no in-app purchases.

### Is Stack Testers Friend free?

Stack Testers Friend is free to download, with no in-app purchases.

### Do SSG On Site or Stack Testers Friend have ads?

Neither SSG On Site nor Stack Testers Friend shows ads.

### Which is updated more often, SSG On Site or Stack Testers Friend?

SSG On Site ships an update every 10 days, and Stack Testers Friend every 7 months. Most recently, SSG On Site was updated on October 17, 2026 and Stack Testers Friend on September 24, 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.*