Nitrox Buddy vs Gas Blender Toolkit
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Nitrox Buddy
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.
- 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
Read full descriptionHide full description
Nitrox Buddy is a no-frills calculator app for nitrox/enriched air divers - use it to quickly calculate the most important data for your dive: Maximum Operating Depth/MOD, Equivalent Air Depth/EAD, Best Mix and PPO2. The app works with imperial or metric measurements, sea or fresh water, and allows you to select the maximum oxygen content and partial pressure. A companion watch app puts lets you perform all these calculations on your wrist.
Gas Blender Toolkit
This comprehensive toolkit assists scuba divers in calculating and blending various gas mixtures like trimix, nitrox, and heliox. It offers features for both partial pressure and continuous blending, cost calculation, and utilizes ideal and real gas models for accuracy. Optimized for larger screens, it serves as a successor to a previous diving application.
- Partial pressure blending
- Continuous blending
- Trimix, nitrox, heliox calculations
- Ideal and real gas models
- Cost calculation
- Top off from storage
Read full descriptionHide full description
Gas Blender Toolkit is a comprehensive, purpose-built calculator for technical and recreational scuba divers who blend their own breathing gases. FUNCTIONS • Partial-pressure gas blending with freely configurable fill order • Continuous / delta-gas blending method • Decanting from a storage bank, with calculation of the number of possible fills • MOD / END tables for standard scuba gases • pSCR loop oxygen-reduction calculation at constant volume ratio • CCR rebreather diluent END calculator for any depth and chosen PPO2 setpoint FEATURES • Real gas (Van der Waals) or ideal gas calculations • Cost calculation for each gas fill • Fully customizable standard gas list • Accounts for gas heating during filling • Clean, fast and easy to use • Available in English, German, Russian and Spanish Gas Blender Toolkit is the completely rewritten successor to the DIR-Wetnotes app, redesigned from the ground
Screenshots
Verdict
The clearest difference is price: Nitrox Buddy at Free against Gas Blender Toolkit's $2.99. Nitrox Buddy also leads on rating (4.9 vs 3.0) and review sentiment (96% vs 60%). Gas Blender Toolkit's advantage is in-app purchases (none vs 1) and update cadence (every 9 days vs every 7 months). On ads and device support there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Nitrox Buddy is free to download; Gas Blender Toolkit costs $2.99 up front. Nitrox Buddy sells 1 one-off in-app purchase. Gas Blender Toolkit asks for nothing beyond the download.
Nitrox Buddy holds the better App Store score, 4.9 against 3.0. That said, the two scores are not equally well evidenced: Nitrox Buddy has 490 ratings behind it against 2, 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 60% of Gas Blender Toolkit's.
Nitrox Buddy ships an update every 7 months, Gas Blender Toolkit every 9 days. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.
| Parameter | Nitrox Buddy | Gas Blender Toolkit |
|---|---|---|
| Price | Free — better | $2.99 |
| Rating | 4.9 (490 ratings) — better | 3.0 (2 ratings) |
| Positive reviews | 95.8% of reviews — better | 60.0% of reviews |
| Number of ratings | 490 — better | 2 |
| Update frequency | Every 7 months | Every 9 days — better |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases — better | Paid |
| Devices | iPhone, Apple Watch | iPhone, iPad, iPod — better |
| Requires iOS | 26.0 | 15.0 — better |
| Further details — not scored | ||
| Size | 6 MB | 3 MB |
| Age rating | 4+ | 4+ |
| Developer | Gereon Steffens | Oleg Gurevich |
Customer experience
Nitrox Buddy
Gas Blender Toolkit
Bugs and requests
Nitrox Buddy
Reported bugs
4 issues- 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
4 requests- 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)
Gas Blender Toolkit
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Nitrox Buddy
- Tip$0.99
Gas Blender Toolkit
No in-app purchases
Questions
Is Nitrox Buddy free?
Is Gas Blender Toolkit free?
Which has better reviews, Nitrox Buddy or Gas Blender Toolkit?
Do Nitrox Buddy or Gas Blender Toolkit have ads?
Which is updated more often, Nitrox Buddy or Gas Blender Toolkit?
Other comparisons
