Nitrox Buddy vs Poseidon Reef
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
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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.
Poseidon Reef
This app helps divers log, plan, and analyze their dives. It offers detailed overviews, customizable dive logs, and advanced planning for various dive types. Connect your dive computer to manage data and firmware.
- Comprehensive dive logging
- Detailed dive planning
- Support for OC and CCR dives
- Unlimited tank support
- Decompression model selection
- Dive computer connectivity
- Cloud backup and firmware updates
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Dive into the deep with Reef, the ultimate tool for every diver regardless of experience, level, or dive style. Designed to enhance and prolong your passion for diving, Reef seamlessly extends your diving experience, both before and after the actual dive. With Reef in your pocket, you're always ready to explore. Dive Log > Get a comprehensive and detailed overview of all your dives. > Easily sort and filter to find specific dives. > Import and export dives effortlessly. > Personalize dives with custom details, photos, location and more. > Engage with your dives using the interactive chart functionality. > Visualize intricate data like tank pressures, pO2, loop temperature, etc.* > Choose the data points you want to see > Zoom in on portions of the dive you are interested in Planner > Keep track of all your upcoming dives with a comprehensive overview. > Sort, filter, and organize your dive plans. > Plan for a single dive or a series of dives. > Suitable for OC (Open Circuit) and CCR (Closed Circuit Rebreather) dives. > Supports an unlimited number of tanks. > Choose between DCAP and Buhlmann decompression models. > Bailout scenario > Configure gas content Device Manager > Connect your Poseidon M28 dive computer through WiFi > View details about connected submodules. > Download, store, and back up your dives in the cloud. > Access vital service information > Monitor total dive time > Stay updated with firmware information. *Only available with Poseidon M28 dive computer
Screenshots
Verdict
The clearest difference is review sentiment: Nitrox Buddy at 96% against Poseidon Reef's 0%. Nitrox Buddy also leads on rating (4.9 vs 3.0) and ads (none vs shown). Poseidon Reef's advantage is in-app purchases (none vs 1) and update cadence (every 5 weeks vs every 7 months). On price 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
Both are free to download. Nitrox Buddy sells 1 one-off in-app purchase. Poseidon Reef 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 468 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 0% of Poseidon Reef's.
Nitrox Buddy ships an update every 7 months, Poseidon Reef every 5 weeks. The most recent releases landed on October 14, 2026 and September 30, 2026 respectively.
| Parameter | Nitrox Buddy | Poseidon Reef |
|---|---|---|
| Price | Free | Free |
| Rating | 4.9 (468 ratings) — better | 3.0 (2 ratings) |
| Positive reviews | 95.7% of reviews — better | 0.0% of reviews |
| Number of ratings | 468 — better | 2 |
| Update frequency | Every 7 months | Every 5 weeks — better |
| Ads | No — better | Yes |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Ad-supported — better |
| Devices | iPhone, iPod, Apple Watch | iPhone, iPad, iPod, Mac — better |
| Requires iOS | 26.0 | 12.1 — better |
| Further details — not scored | ||
| Size | 6 MB | 58 MB |
| Age rating | 4+ | 4+ |
| Developer | Gereon Steffens | Poseidon Diving Systems AB |
Customer experience
Nitrox Buddy
Poseidon Reef
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)
Poseidon Reef
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Nitrox Buddy
- Tip$0.99
Poseidon Reef
No in-app purchases
Questions
Is Nitrox Buddy free?
Is Poseidon Reef free?
Which has better reviews, Nitrox Buddy or Poseidon Reef?
Do Nitrox Buddy or Poseidon Reef have ads?
Which is updated more often, Nitrox Buddy or Poseidon Reef?
Other comparisons
