# Trimix Tools vs myPSS

The clearest difference is price: myPSS at Free against Trimix Tools's $6.99. Trimix Tools's advantage is update cadence (every 5 months vs every 42 months) and ratings volume (5 vs 1). On rating, ads, in-app purchases and device support there is nothing between them.

myPSS is free to download; Trimix Tools costs $6.99 up front. Neither carries in-app purchases, so what you see is what you pay.

On the App Store both sit at effectively the same score — 5.0 for Trimix Tools against 5.0 for myPSS. That said, the two scores are not equally well evidenced: Trimix Tools has 5 ratings behind it against 1, so its average is the more settled of the two.

Trimix Tools ships an update every 5 months, myPSS every 42 months. The most recent releases landed on October 14, 2026 and October 4, 2026 respectively.

## The numbers

| Metric | Trimix Tools | myPSS |
| --- | --- | --- |
| Price | $6.99 | **Free** |
| Rating | [5.0 (5 ratings)](https://appshunter.io/ios/app/trimix-tools/id289220808/reviews) | [5.0 (1 ratings)](https://appshunter.io/ios/app/mypss/id904666792/reviews) |
| Number of ratings | **5** | 1 |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | **Every 5 months** | Every 42 months |
| Monetization | Paid | **Free** |
| Size | 6 MB | 64 MB |
| Requires iOS | 15.6 | **15.1** |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone, iPad, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Greg Mclaughlin](https://appshunter.io/developer/284919983) | [Margherita Aucelli](https://appshunter.io/developer/904666795) |

## What reviewers say

### Trimix Tools

[App page](https://appshunter.io/ios/app/trimix-tools/id289220808)

This app provides essential tools for divers to plan and blend Trimix gases. It calculates optimal mixes based on depth, oxygen partial pressure, and equivalent narcotic depth, and supports various cylinder filling scenarios. Calculations are available offline and can be customized with saved settings.

**Highlights:** Trimix blending and planning, Depth and partial pressure calculations, Equivalent Narcotic Depth (END) calculation, Saltwater and freshwater support, Cylinder filling and bleed down calculations, Metric and Imperial system support, Offline functionality, Saved settings and custom mixes

**Features:** Vision Pro support

**In-app purchases:** none


### myPSS

[App page](https://appshunter.io/ios/app/mypss/id904666792)

This application serves as a dedicated platform for members and instructors of PSS. It provides a centralized hub for information and communication within the PSS community.

**Highlights:** Dedicated platform for PSS members, Dedicated platform for PSS instructors, Centralized information hub, Community communication tool

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

**In-app purchases:** none


## Frequently asked questions

### Is Trimix Tools free?

Trimix Tools costs $6.99, with no in-app purchases.

### Is myPSS free?

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

### Which has better reviews, Trimix Tools or myPSS?

Trimix Tools and myPSS are both rated 5.0 out of 5 on the App Store, from 5 and 1 ratings respectively.

### Do Trimix Tools or myPSS have ads?

Neither Trimix Tools nor myPSS shows ads.

### Which is updated more often, Trimix Tools or myPSS?

Trimix Tools ships an update every 5 months, and myPSS every 42 months. Most recently, Trimix Tools was updated on October 14, 2026 and myPSS on October 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.*