# GRAT: Mountain Storm Weather — Ski tour & summit storm risk > Ski tour & summit storm risk (iPhone/iPad app by Bahadır CETIN.) - Source: https://appshunter.io/ios/app/grat-mountain-storm-weather/id6812671374 (this page in markdown: same URL + `.md`) - Developer: [Bahadır CETIN](https://appshunter.io/developer/6812671376) - Category: Weather, Utilities - Price: Free with in-app purchases - Age rating: 4+ - Requires: iOS 17.0 · 6 MB - Languages: American English, German (Germany), Turkish - Released: 2026-10-14 - Data updated: 2026-11-06 ## What is GRAT? GRAT is a decision-support tool for mountaineers, ski tourers and hikers. It combines official weather warnings, high-resolution weather models and station measurements into one risk level for your position and altitude: Safe, Watch, Danger. WINTER MODE Turns on by itself when there is snow cover, snowfall, or a freezing level below you. • The lowest level reads "Low weather risk" instead of "Safe". • Fresh snow (past and next 24 hours), snow depth, time to sunset • How fast exposed skin can freeze (Environment Canada wind chill table) • GRAT does not assess avalanche danger. One tap opens your region's official avalanche bulletin. WHAT GRAT SHOWS • Shower and thunderstorm risk: at what time, according to which model • Wind gusts and feels-like temperature (hypothermia risk) • Official warnings (DWD in Germany, MeteoAlarm across Europe, NWS in the US); translate warnings in other languages on your device • Radar: our own radar for Europe (EUMETNET OPERA and DWD), NOAA in the continental US • Map with shaded relief and contour lines (Copernicus DEM) • Pressure trend from your iPhone's barometer COMPANION MODE Start it before you set out: GRAT re-evaluates the risk regularly along the way and sends a notification when it rises. No notifications are sent while the app is closed, and delivery depends on iOS and may fail. Distance and barometer measurements pause automatically while you drive. At the end of the trip you can mark whether the alerts were accurate. TO BE HONEST • GRAT does not make decisions for you; your own observation and experience always come first. • Without data the app does not say "safe" — it says "cannot be evaluated". • No alerts are sent while the app is closed. PRIVACY No account, no ads, no tracking. Your location is rounded to about 110 m. Forecasts and radar come from our own data server, which does not store your location or your IP address. GRAT PRO Core risk information (risk level, official warnings, radar) is always free. Pro adds unlimited Companion Mode (free: 2 trips per month), offline route forecasts, full history with export and the Live Activity. Monthly, yearly (14-day free trial) or a one-time lifetime purchase. Family Sharing included. Terms of Use (EULA): https://gratweather.com/terms/ Privacy Policy: https://gratweather.com/privacy/ ## Pricing and in-app purchases Base price: Free. **Subscriptions** | Subscription | Price | Period | | --- | --- | --- | | GRAT Pro · Yearly | $24.99 | per year | | GRAT Pro · Monthly | $3.99 | per month | **One-time purchases** | Purchase | Price | Type | | --- | --- | --- | | GRAT Pro · Lifetime | $49.99 | one-time | ## Is GRAT safe? Not enough ratings yet to assess GRAT. ## Is GRAT legit? GRAT: Mountain Storm Weather has limited verification signals. The AppsHunter Legitimacy Score for GRAT is 58 out of 100 points across 7 verification signals from App Store and developer data. ## Version history (last 5 releases) ### 1.2.6 — 2026-11-05 Small improvements. ### 1.2.5 — 2026-11-04 New: the “Calculated for you” card. The panel now shows what the risk was worked out from: your altitude, the terrain, the time and the weather model. The card also lists what we don't know. “What would change it”: does the result change 300 m lower, 300 m higher or a few hours later? Same forecast, only altitude and time changed. Send the card as an image to your climbing partner or save it to Photos. The app never reads your library; it only adds to it. Fixed: on slow ascents, elevation gain was undercounted. The source of the model data (Open-Meteo, ECMWF, CC BY 4.0) is now listed in Settings and Statistics. ### 1.2.4 — 2026-10-30 The app itself is unchanged in this update. We refreshed the screenshots on the App Store page. Since 1.2.2: unfold iPhone Duo and turn it sideways, or hold your iPhone in landscape, and the content sits in a readable column in the middle. Winter mode, our own radar and the relief map arrived in 1.2: in snowy conditions fresh snow, snow depth and frostbite time; no avalanche rating, one tap to the official bulletin. ### 1.2.3 — 2026-10-29 The app itself is unchanged in this update. We added screenshots for the iPhone Duo inner screen to the App Store page. Since 1.2.2: unfold iPhone Duo and turn it sideways, or hold your iPhone in landscape, and the content sits in a readable column in the middle. Winter mode, our own radar and the relief map arrived in 1.2: in snowy conditions fresh snow, snow depth and frostbite time; no avalanche rating, one tap to the official bulletin. ### 1.2.2 — 2026-10-28 Unfold iPhone Duo and turn it sideways, or hold your iPhone in landscape, and the content now sits in a readable column in the middle. Lines no longer run across the whole screen. On the iPhone Duo outer screen, the first card in the Companion tab no longer touches the top edge. Winter mode, our own radar and the relief map arrived in 1.2: in snowy conditions fresh snow, snow depth and frostbite time; no avalanche rating, one tap to the official bulletin. --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-11-06.*