# Nitrox Buddy vs ATMOS

The clearest difference is review sentiment: Nitrox Buddy at 96% against ATMOS's 8%. Nitrox Buddy also leads on rating (4.9 vs 1.7) and ratings volume (490 vs 23). ATMOS's advantage is in-app purchases (none vs 1) and update cadence (every 5 weeks vs every 7 months). On price, ads and device support there is nothing between them.

Both are free to download. Nitrox Buddy sells 1 one-off in-app purchase. ATMOS asks for nothing beyond the download.

Nitrox Buddy holds the better App Store score, 4.9 against 1.7. That said, the two scores are not equally well evidenced: Nitrox Buddy has 490 ratings behind it against 23, so its average is the more settled of the two. Written reviews point the same way: 96% of Nitrox Buddy's written reviews are positive against 8% of ATMOS's.

Nitrox Buddy ships an update every 7 months, ATMOS every 5 weeks. Both last shipped on October 24, 2026.

## The numbers

| Metric | Nitrox Buddy | ATMOS |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (490 ratings)](https://appshunter.io/ios/app/nitrox-buddy/id572411073/reviews)** | [1.7 (23 ratings)](https://appshunter.io/ios/app/atmos-diving-logbooks/id1448666557/reviews) |
| Number of ratings | **490** | 23 |
| Positive reviews | **95.8% of reviews** | 7.7% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 5 weeks** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 6 MB | 125 MB |
| Requires iOS | 26.0 | **14.0** |
| Devices | iPhone, Apple Watch | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Gereon Steffens](https://appshunter.io/developer/493030228) | [ATMOS CO., LTD.](https://appshunter.io/developer/1448666556) |

## What reviewers say

### Nitrox Buddy

[App page](https://appshunter.io/ios/app/nitrox-buddy/id572411073)

This application serves as a straightforward calculator for nitrox and enriched air divers. It quickly computes essential dive data such as Maximum Operating Depth (MOD), Equivalent Air Depth (EAD), Best Mix, and Partial Pressure of Oxygen (PPO2). It supports both imperial and metric units and offers a companion watch app for on-the-go calculations.

**Highlights:** Calculate MOD, EAD, Best Mix, PPO2, Imperial and metric unit support, Sea and fresh water options, Selectable max oxygen content, Selectable max partial pressure, Companion watch app

**Features:** macOS Compatibility, Apple Watch app, Vision Pro support

**In-app purchases (1)**

| Purchase | Price | Billing |
| --- | --- | --- |
| Tip | $0.99 | one-time |

**What reviewers like**

- 👍 Easy to use
- 🚀 Quick calculations
- ✅ Accurate results
- 💡 Free to use
- 🎯 Essential for Nitrox divers

**What reviewers complain about**

- 📱 Ugly iPad icon
- ⚠️ MOD calculation limited to 40% O2 in older versions
- ⚠️ MOD calculation limited to 50% O2 in older versions
- ⚠️ Needs to work with older iOS versions

**Reported bugs**

- iPad icon is ugly
- MOD limit of 50% O2 despite 100% O2 setting (resolved)
- MOD limit of 40% O2 (older version)
- Does not work with older iOS versions

**Requested features**

- Add MOD 1.5 option
- Allow MOD calculation up to 100% O2 and indicate max exposure duration
- Change color for inappropriate mixes (e.g., 50% at 40m)
- Support older iOS versions (5 & 6)


### ATMOS

[App page](https://appshunter.io/ios/app/atmos-diving-logbooks/id1448666557)

This app wirelessly syncs dive logs from compatible dive computers. Users can view device information, edit dive log details, and export data in UDDF format. It also integrates with HealthKit to share dive-related health metrics.

**Highlights:** Wireless dive log sync, Device information check, Edit dive log details, Export to UDDF format, HealthKit integration

**In-app purchases:** none


## Frequently asked questions

### Is Nitrox Buddy free?

Nitrox Buddy is free to download, with in-app purchases available.

### Is ATMOS free?

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

### Which has better reviews, Nitrox Buddy or ATMOS?

Nitrox Buddy is rated higher. Nitrox Buddy averages 4.9 out of 5 from 490 ratings, while ATMOS averages 1.7 from 23 ratings.

### Do Nitrox Buddy or ATMOS have ads?

Neither Nitrox Buddy nor ATMOS shows ads.

### Which is updated more often, Nitrox Buddy or ATMOS?

Nitrox Buddy ships an update every 7 months, and ATMOS every 5 weeks. Most recently, Nitrox Buddy was updated on October 24, 2026 and ATMOS on October 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.*