coolAltitude vs SubStandard
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
coolAltitude
This professional tool assists IFR pilots in cold weather with temperature corrections for instrument approaches. It integrates weather, runway, and de-/anti-icing data into a clear workflow to reduce workload and enhance situational awareness during flight preparation.
- Temperature-corrected altitude calculations for various approaches
- Integrated weather and runway condition data
- De-/anti-icing support with holdover time timers
- SNOWTAM decoding and braking action information
- Save and share approach presets and operational data
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coolAltitude is a professional aviation tool and calculator for IFR pilots operating in cold-weather conditions. It assists with temperature corrections during instrument approaches and integrates weather, runway and de-/anti-icing data into a single, clear workflow. Designed to reduce workload and improve situational awareness during flight preparation, coolAltitude focuses on accuracy, clarity and operational usability. Some advanced features require a paid subscription. -------------------------------- What coolAltitude does • Calculates temperature-corrected altitudes for ILS (CAT I), RNAV/GNSS, VOR and NDB approaches • Requires minimal data entry, using consistent color coding for immediate interpretation • Displays corrected altitudes along the entire approach profile at relevant DME distances • Supports flight path angle (FPA) calculations for FPA-enabled aircraft • Provides vertical speed reference tables (corrected and uncorrected) for various ground speeds • Includes QNH to QFE conversion tables with temperature corrections -------------------------------- Integrated weather and runway information • Live METAR interaction with automatic propagation of relevant values, including temperature (requires subscription) • SNOWTAM decoding with braking action information • RCAM (Runway Condition Assessment Matrix) based on ICAO GRF • Support for DME shift, including threshold, touchdown zone and displaced DME references -------------------------------- De-/Anti-icing support (requires subscription) • FAA Holdover Time (HOT) Guidelines for multiple fluid types and manufacturers • Integrated HOT countdown timer to track minimum and maximum recommended holdover times • Reference tables supporting assessment of snowfall intensity • Structured storage and sharing of airport-specific de-/anti-icing procedures -------------------------------- Saved and shared data (requires subscription) • Save and reload approach presets for individual airports and procedures • Share verified, structured operational data with other users • Local override of shared data when required -------------------------------- Built for professional use coolAltitude is built by pilots, for pilots. It is designed to support decision-making during high-workload phases without replacing approved procedures. -------------------------------- Important notice coolAltitude is an advisory tool only. It is not certified for operational use and does not replace approved documentation. Use in flight operations requires approval and operation as part of the operator’s Electronic Flight Bag (EFB) in accordance with applicable regulations. -------------------------------- coolAltitude does not replace your procedures. It helps you apply them correctly, even on the coldest days. -------------------------------- Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/
SubStandard
This aviation utility app simplifies applying cold temperature corrections for altitudes. It allows users to save frequently used altitude sets for rapid retrieval, enhancing efficiency in flight planning.
- Cold temperature corrections
- Altitude set storage
- Quick access to saved altitudes
- Easy to use interface
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SubStandard is an easy to use app to apply cold temperature corrections in aviation. Moreover, it lets you store sets of altitudes for quick access later on.
Screenshots
Verdict
coolAltitude and SubStandard both sit at 5.0 stars, but that hides the real split: 75% of coolAltitude's written reviews are positive against 0% of SubStandard's. coolAltitude also leads on ratings volume (7 vs 2). SubStandard's advantage is price (Free vs $7.99) and in-app purchases (none vs 2). On rating, update cadence, 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
SubStandard is free to download; coolAltitude costs $7.99 up front. coolAltitude sells 2 in-app purchases, starting at $7.99 per year. SubStandard asks for nothing beyond the download.
On the App Store both sit at effectively the same score — 5.0 for coolAltitude against 5.0 for SubStandard. Both are backed by a comparable volume of ratings — 7 and 2 respectively. Written reviews are what separate them: 75% of coolAltitude's written reviews are positive against 0% of SubStandard's.
coolAltitude ships an update every 5 months, SubStandard every 7 months. The most recent releases landed on September 7, 2026 and September 9, 2026 respectively.
| Parameter | coolAltitude | SubStandard |
|---|---|---|
| Price | $7.99 | Free — better |
| Rating | 5.0 (7 ratings) | 5.0 (2 ratings) |
| Positive reviews | 75.0% of reviews — better | 0.0% of reviews |
| Number of ratings | 7 — better | 2 |
| Update frequency | Every 5 months — better | Every 7 months |
| Ads | No | No |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | Free — better |
| Devices | iPhone, iPad | iPhone, iPad, iPod — better |
| Requires iOS | 17.0 | 12.0 — better |
| Further details — not scored | ||
| Size | 49 MB | 33 MB |
| Age rating | 17+ | 4+ |
| Developer | SilkIdea s.r.o. | iService Ottner Röck |
Customer experience
coolAltitude
SubStandard
In-app purchases
coolAltitude
- De & Anti-Icing Pro$7.991 Year
- Save & Retrieve Approach Data$7.991 Year
SubStandard
No in-app purchases








