# Nitrox Buddy vs Kratos AI

The clearest difference is in-app purchases: Kratos AI at none against Nitrox Buddy's 1. Kratos AI also leads on update cadence (every 3 days vs every 7 months) and iOS requirement (15.0 vs 26.0). 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. Kratos AI asks for nothing beyond the download.

Nitrox Buddy ships an update every 7 months, Kratos AI every 3 days. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.

## The numbers

| Metric | Nitrox Buddy | Kratos AI |
| --- | --- | --- |
| Price | Free | Free |
| Rating | **[4.9 (490 ratings)](https://appshunter.io/ios/app/nitrox-buddy/id572411073/reviews)** | — |
| Number of ratings | **490** | — |
| Positive reviews | 95.8% of reviews | — |
| In-app purchases | Yes | **No** |
| Ads | No | No |
| Update frequency | Every 7 months | **Every 3 days** |
| Monetization | Free with in-app purchases | — |
| Size | 6 MB | 16 MB |
| Requires iOS | 26.0 | **15.0** |
| Devices | iPhone, Apple Watch | **iPhone, iPad, iPod** |
| Age rating | 4+ | 4+ |
| Developer | [Gereon Steffens](https://appshunter.io/developer/493030228) | [Kratos AI](https://appshunter.io/developer/1875487504) |

## 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)


### Kratos AI

[App page](https://appshunter.io/ios/app/kratos-ai/id6758879142)

**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 Kratos AI free?

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

### Do Nitrox Buddy or Kratos AI have ads?

Neither Nitrox Buddy nor Kratos AI shows ads.

### Which is updated more often, Nitrox Buddy or Kratos AI?

Nitrox Buddy ships an update every 7 months, and Kratos AI every 3 days. Most recently, Nitrox Buddy was updated on October 24, 2026 and Kratos AI on October 25, 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.*