Gas Blender Toolkit vs DecoPlan
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
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
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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
DecoPlan
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DecoPlan is a universal dive planner for open-circuit and rebreather (CCR) divers, built around two published decompression models: VPM-B with the critical-volume algorithm and Bühlmann ZHL-16C with gradient factors. NO-DECO PLANNER • No-decompression limits for air and nitrox, safety stop, gas needed • Repetitive dives with surface intervals, altitude and fresh water • NDL table for every mix at a glance TECHNICAL PLANNER • Multi-level profiles, any number of gases (nitrox, trimix, oxygen) • Automatic deco-gas switches by ppO₂, last stop at 3 or 6 m, air breaks on O₂ • Runtime table with ppO₂, END, ceiling; depth profile with the ceiling band • Tissue loading graph, CNS/OTU, gas consumption per cylinder, minimum gas, turn pressure • Model comparison: the same dive through six model settings side by side • Contingency grid: what happens 3/6/9 m deeper or 5/10/15 min longer • Lost-gas scenarios, wet-notes text export REBREATHER (CCR) · PRO • Setpoints for bottom and deco, setpoint switching by depth • Diluent plus up to ten bailout cylinders with their own mixes • Open-circuit bailout: a failure at the turn point (half the bottom time) with the swim back, or at the end of the bottom time • Bailout advisor: how many cylinders, which mixes, switch depths and sizes for the planned depth TOOLS • MOD, END, EAD, gas density, best mix, partial-pressure blending, SAC calculator Six languages: English, Russian, German, Spanish, Simplified and Traditional Chinese. All features, including the Pro feature set (CCR and SCR, VPM-B and VPM-B/GFS, multi-level profiles, more than two deco gases, oxygen breaks, contingency and lost-gas plans, model comparison, team planning, sync between devices), are free for 30 days from download, or from first launch if the download date is unavailable. No in-app purchase or subscription can be bought at this time, and the app contains no advertising. A genuine paid annual subscription continues until the end of the term already paid for, and a lifetime purchase remains valid. Any other access previously granted to an existing account is honored only for the period already granted and does not become unlimited. Existing plans, dive logs, equipment, trips, photos and account data are preserved. IMPORTANT DecoPlan is a planning tool for trained divers. Every decompression model is an approximation; verify plans with another planner and your dive computer, keep gas reserves, and never dive beyond your training. The app is not a medical device and does not guarantee safety. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://decoplan.dvpdnsca.org/privacy.html © 2026 Dmitri Plotnikov (dvp)
Screenshots
Verdict
The clearest difference is price: DecoPlan at Free against Gas Blender Toolkit's $2.99. DecoPlan also leads on update cadence (every 2 days vs every 9 days). Gas Blender Toolkit's advantage is ads (none vs shown) and iOS requirement (15.0 vs 17.0). On in-app purchases 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
DecoPlan is free to download; Gas Blender Toolkit costs $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.
Gas Blender Toolkit ships an update every 9 days, DecoPlan every 2 days. Both last shipped on October 29, 2026.
| Parameter | Gas Blender Toolkit | DecoPlan |
|---|---|---|
| Price | $2.99 | Free — better |
| Rating | 3.0 (2 ratings) — better | — |
| Positive reviews | 60.0% of reviews | — |
| Number of ratings | 2 — better | — |
| Update frequency | Every 9 days | Every 2 days — better |
| Ads | No — better | Yes |
| In-app purchases | No | No |
| Monetization | Paid | — |
| Devices | iPhone, iPad, iPod — better | iPhone, iPad |
| Requires iOS | 15.0 — better | 17.0 |
| Further details — not scored | ||
| Size | 3 MB | 74 MB |
| Age rating | 4+ | 9+ |
| Developer | Oleg Gurevich | Dmitri Plotnikov |
In-app purchases
Gas Blender Toolkit
No in-app purchases
DecoPlan
No in-app purchases









