# iDeco Pro vs Halcyon Dive Systems

The clearest difference is price: Halcyon Dive Systems at Free against iDeco Pro's $8.99. Halcyon Dive Systems also leads on rating (5.0 vs 3.9) and update cadence (every 3 weeks vs every 18 months). iDeco Pro's advantage is device support (3 vs 1) and iOS requirement (7.0 vs 16.0). On ratings volume, ads and in-app purchases there is nothing between them.

Halcyon Dive Systems is free to download; iDeco Pro costs $8.99 up front. Neither carries in-app purchases, so what you see is what you pay.

Halcyon Dive Systems holds the better App Store score, 5.0 against 3.9. Both are backed by a comparable volume of ratings — 10 and 8 respectively.

iDeco Pro ships an update every 18 months, Halcyon Dive Systems every 3 weeks. The most recent releases landed on October 29, 2026 and October 21, 2026 respectively.

## The numbers

| Metric | iDeco Pro | Halcyon Dive Systems |
| --- | --- | --- |
| Price | $8.99 | **Free** |
| Rating | [3.9 (10 ratings)](https://appshunter.io/ios/app/ideco-pro/id329772936/reviews) | **[5.0 (8 ratings)](https://appshunter.io/ios/app/halcyon-dive-systems-diving/id6738069654/reviews)** |
| Number of ratings | **10** | 8 |
| Positive reviews | 52.0% of reviews | — |
| In-app purchases | No | No |
| Ads | No | No |
| Update frequency | Every 18 months | **Every 3 weeks** |
| Monetization | Paid | **Ad-supported** |
| Size | 3 MB | 162 MB |
| Requires iOS | **7.0** | 16.0 |
| Devices | **iPhone, iPad, iPod** | iPhone |
| Age rating | 4+ | 4+ |
| Developer | [B2 Prototech LLC](https://appshunter.io/developer/1575972363) | [Halcyon Dive Systems](https://appshunter.io/developer/1779189368) |

## What reviewers say

### iDeco Pro

[App page](https://appshunter.io/ios/app/ideco-pro/id329772936)

This app is a comprehensive dive planner for technical divers, supporting both open circuit and closed-circuit rebreather (CCR) diving. It calculates decompression stops, gas usage, CNS and OTU exposure, and surface intervals. The app also includes a gas mixer for planning custom gas blends.

**Highlights:** Open Circuit and CCR dive planning, Decompression stop calculation, Gas usage and CNS/OTU tracking, Surface interval tracking, Gas fill/mixer functionality, Bailout planning for overhead environments, Configurable settings within the app

**Features:** macOS Compatibility, 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 iDeco Pro free?

iDeco Pro costs $8.99, 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, iDeco Pro or Halcyon Dive Systems?

Halcyon Dive Systems is rated higher. iDeco Pro averages 3.9 out of 5 from 10 ratings, while Halcyon Dive Systems averages 5.0 from 8 ratings.

### Do iDeco Pro or Halcyon Dive Systems have ads?

Neither iDeco Pro nor Halcyon Dive Systems shows ads.

### Which is updated more often, iDeco Pro or Halcyon Dive Systems?

iDeco Pro ships an update every 18 months, and Halcyon Dive Systems every 3 weeks. Most recently, iDeco Pro 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.*