# Nitrox Buddy vs NDL

The clearest difference is in-app purchases: NDL at none against Nitrox Buddy's 1. NDL also leads on iOS requirement (12.0 vs 26.0). Nitrox Buddy's advantage is review sentiment (96% vs 67%). On price, update cadence, ads and device support there is nothing between them.

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

Nitrox Buddy ships an update every 7 months, NDL every 5 months. The most recent releases landed on October 14, 2026 and September 21, 2026 respectively.

## The numbers

| Metric | Nitrox Buddy | NDL |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (468 ratings)](https://appshunter.io/ios/app/nitrox-buddy/id572411073/reviews)** | — |
| Number of ratings | **468** | — |
| Positive reviews | **95.7% of reviews** | 66.7% of reviews |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 5 months** |
| Monetization | Free with in-app purchases | **Free** |
| Size | 6 MB | 17 MB |
| Requires iOS | 26.0 | **12.0** |
| Devices | **iPhone, iPod, Apple Watch** | iPhone, iPod |
| Age rating | 4+ | 4+ |
| Developer | [Gereon Steffens](https://appshunter.io/developer/493030228) | [NDL, UCH](https://appshunter.io/developer/1278307433) |

## 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

**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)


### NDL

[App page](https://appshunter.io/ios/app/ndl/id1278307434)

Confirm your diver or freediver status online and save electronic certificates offline. This app offers a free log-book and No-decompression limit planner, along with the latest news from the National Dive League. Professionals can also manage certificates and access the NDL Professional Zone.

**Highlights:** Confirm diver status online, Save electronic certificates offline, Free log-book, No-decompression limit planner, Latest news from National Dive League, Manage certificates for professionals

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

**In-app purchases:** none


## Frequently asked questions

### Is Nitrox Buddy free?

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

### Is NDL free?

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

### Do Nitrox Buddy or NDL have ads?

Neither Nitrox Buddy nor NDL shows ads.

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

Nitrox Buddy ships an update every 7 months, and NDL every 5 months. Most recently, Nitrox Buddy was updated on October 14, 2026 and NDL on September 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.*