# Trimix Tools vs Halcyon Dive Systems

The clearest difference is price: Halcyon Dive Systems at Free against Trimix Tools's $6.99. Halcyon Dive Systems also leads on update cadence (every 3 weeks vs every 4 months). Trimix Tools's advantage is device support (4 vs 1). On rating, ratings volume, ads and in-app purchases there is nothing between them.

Halcyon Dive Systems 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 Halcyon Dive Systems. Both are backed by a comparable volume of ratings — 5 and 8 respectively.

Trimix Tools ships an update every 4 months, Halcyon Dive Systems every 3 weeks. The most recent releases landed on October 29, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | Trimix Tools | Halcyon Dive Systems |
| --- | --- | --- |
| Price | $6.99 | **Free** |
| Rating | [5.0 (5 ratings)](https://appshunter.io/ios/app/trimix-tools/id289220808/reviews) | [5.0 (8 ratings)](https://appshunter.io/ios/app/halcyon-dive-systems-diving/id6738069654/reviews) |
| Number of ratings | 5 | **8** |
| Positive reviews | 100.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 4 months | **Every 3 weeks** |
| Monetization | Paid | **Ad-supported** |
| Size | 6 MB | 162 MB |
| Requires iOS | **15.6** | 16.0 |
| Devices | **iPhone, iPad, iPod, Mac** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [Greg Mclaughlin](https://appshunter.io/developer/284919983) | [Halcyon Dive Systems](https://appshunter.io/developer/1779189368) |

## 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


### Halcyon Dive Systems

[App page](https://appshunter.io/ios/app/halcyon-dive-systems-diving/id6738069654)

This app helps divers log, track, and share their underwater experiences. It offers integration with dive computers, personalized settings, and a community forum for connecting with other divers.

**Highlights:** Symbios integration for dive computer settings, Detailed dive logging and progress tracking, Social logbook for sharing dive stories, Connect with a global diving community, Personalized dive tips and advice, Exclusive benefits for Halcyon owners

**Features:** macOS Compatibility, Apple Wallet, 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 Halcyon Dive Systems free?

Halcyon Dive Systems is free to download, with no in-app purchases.

### Which has better reviews, Trimix Tools or Halcyon Dive Systems?

Trimix Tools and Halcyon Dive Systems are both rated 5.0 out of 5 on the App Store, from 5 and 8 ratings respectively.

### Do Trimix Tools or Halcyon Dive Systems have ads?

Neither Trimix Tools nor Halcyon Dive Systems shows ads.

### Which is updated more often, Trimix Tools or Halcyon Dive Systems?

Trimix Tools ships an update every 4 months, and Halcyon Dive Systems every 3 weeks. Most recently, Trimix Tools was updated on October 29, 2026 and Halcyon Dive Systems on October 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.*