Comparison

coolAltitude vs GRF Snowtam

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

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.

Highlights
  • 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
Features
Read full description

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/

About

GRF Snowtam

Decode aviation weather reports with this tool. It handles Global Reporting Format (GRF) and older Snowtam formats, converts visibility and temperature units, and calculates altitude corrections for cold weather.

Highlights
  • GRF decoder
  • Snowtam decoder
  • MOTNE decoder
  • Visibility converter
  • Temperature converter
  • Altitude correction calculator
Features
Read full description

Complete and Accurate GRF decoder (New format GRF - global reporting format) to decode RCAM. Complete and Accurate Snowtam decoder (old format - used in Russia). MOTNE Decoder (Old format for Runway Condition Code) Converter for U.S. Visibility SM/m table, and temperatures Altitude correction calculator for cold Temperatures enjoy!

Screenshots

coolAltitude4 screens
GRF Snowtam4 screens

Verdict

The call

The clearest difference is review sentiment: coolAltitude at 75% against GRF Snowtam's 0%. coolAltitude also leads on rating (5.0 vs 1.0) and ratings volume (7 vs 1). GRF Snowtam's advantage is in-app purchases (none vs 2) and price ($1.99 vs $7.99). On 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

CostPrice · In-app purchases · Ads · Monetization

coolAltitude costs $7.99 and GRF Snowtam $1.99 up front. coolAltitude sells 2 in-app purchases, starting at $7.99 per year. GRF Snowtam asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

coolAltitude holds the better App Store score, 5.0 against 1.0. That said, the two scores are not equally well evidenced: coolAltitude has 7 ratings behind it against 1, so its average is the more settled of the two. Written reviews point the same way: 75% of coolAltitude's written reviews are positive against 0% of GRF Snowtam's.

UpkeepUpdate frequency

coolAltitude ships an update every 5 months, GRF Snowtam every 4 months. Both last shipped on September 7, 2026.

Scorecard7 real differences · 3 level
coolAltitude versus GRF Snowtam: the parameters behind the verdict, then further details
ParametercoolAltitudeGRF Snowtam
Price$7.99$1.99 — better
Rating5.0 (7 ratings) — better1.0 (1 ratings)
Positive reviews75.0% of reviews — better0.0% of reviews
Number of ratings7 — better1
Update frequencyEvery 5 monthsEvery 4 months — better
AdsNoNo
In-app purchasesYesNo — better
MonetizationFree with in-app purchases — betterPaid
DevicesiPhone, iPadiPhone, iPod
Requires iOS17.015.6 — better
Further details — not scored
Size49 MB9 MB
Age rating17+4+
DeveloperSilkIdea s.r.o.Pedro Isidoro

Customer experience

coolAltitude

All ratings7 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive75.0%
Neutral0.0%
Negative25.0%

GRF Snowtam

All ratings1 ratings
Positive0.0%
Neutral0.0%
Negative100.0%
Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

In-app purchases

2 purchases

coolAltitude

Subscriptions2
  • De & Anti-Icing Pro$7.991 Year
  • Save & Retrieve Approach Data$7.991 Year
None

GRF Snowtam

No in-app purchases

Questions

Is coolAltitude free?
coolAltitude costs $7.99, and also offers in-app purchases.
Is GRF Snowtam free?
GRF Snowtam costs $1.99, with no in-app purchases.
Which has better reviews, coolAltitude or GRF Snowtam?
coolAltitude is rated higher. coolAltitude averages 5.0 out of 5 from 7 ratings, while GRF Snowtam averages 1.0 from 1 ratings.
Do coolAltitude or GRF Snowtam have ads?
Neither coolAltitude nor GRF Snowtam shows ads.
Which is updated more often, coolAltitude or GRF Snowtam?
coolAltitude ships an update every 5 months, and GRF Snowtam every 4 months. Most recently, coolAltitude was updated on September 7, 2026 and GRF Snowtam on September 7, 2026.

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