Gustline — Privacy Policy

Last updated: August 13, 2026

Gustline is a wind and weather app, built by Joel Askling. This policy covers both the iOS and Android apps (com.joelaskling.windscout).

The short version

Gustline has no accounts, no ads, and no crash-reporting SDKs, and it doesn’t sell or share your data. It uses your device’s location to fetch a wind forecast and show your position on the on-screen map, and it caches that forecast on your device so the app still works with no signal. It also sends one anonymous signal when the app opens, so usage can be counted — never anything tied to you individually. Three outside services are involved in making that work — Open-Meteo (weather data), Mapbox (the map), and Aptabase (anonymous usage counts) — described below.

Location

Gustline asks for location access “while using the app” only. It never requests background/”Always” access, and it never reads your location when the app isn’t open.

Your location is used to:

• Request the wind forecast for where you are (sent to Open-Meteo, see below)
• Show your position on the on-screen map, while the app is open and in the foreground
• Work out compass heading, using your device’s built-in sensors — this never leaves the device

If you deny or later revoke location access, Gustline will prompt you to grant it again (with a link to your device’s Settings) rather than silently failing. The forecast and map won’t work without it.

What gets sent off your device, and to whom

Open-Meteo (open-meteo.com), for the weather forecast:

• Your coordinates, rounded to roughly 11 meters of precision, are sent with each forecast request. There’s no account and no API key involved, and nothing ties separate requests back to you individually.
• Open-Meteo’s infrastructure logs IP addresses for up to 90 days for abuse prevention and usage monitoring, then deletes them — standard handling for anyone calling their API, not something Gustline adds on top. See Open-Meteo’s terms.

Mapbox (mapbox.com), for the on-screen map:

• Mapbox’s SDK sends its own anonymized telemetry by default: general location, altitude and accuracy, a session ID that rotates every 24 hours, and your IP address, which Mapbox uses to improve its maps. Mapbox anonymizes this on-device before it reaches their servers and doesn’t attach it to an advertising or personal identifier. See Mapbox’s privacy policy and their data privacy FAQ.

Aptabase (aptabase.com), for basic, anonymous usage analytics:

• Gustline sends one event when the app opens, so how many people use it can be counted. Nothing else is tracked.
• Aptabase never collects device identifiers (no Device ID, hardware identifier, etc.) and never stores your IP address as-is. Instead, sessions are grouped using a one-way hash of your IP, device/OS info, and a salt that rotates every day — this means the same install can’t be linked across two different days, let alone to you personally.
• Not used for advertising or any kind of cross-app tracking. Data is hosted in the EU and kept for up to 5 years; because it can’t be traced back to an individual, it can’t be looked up or deleted for a specific person. See Aptabase’s privacy policy.

None of these services are used for advertising, and Gustline doesn’t send any of them anything beyond what’s described above.

What stays on your device

The forecast, once fetched, and your settings (units, clock format) are cached locally so the app works offline. This local cache is never uploaded anywhere. Uninstalling the app deletes it — there’s no account or server-side copy to also delete, because none exists.

What Gustline doesn’t do

No accounts or sign-in. No crash-reporting SDKs. No advertising or advertising identifiers. No cross-app or cross-day tracking. No user-generated content. No sale or sharing of your data beyond the three services above, which exist to provide the forecast, map, and basic usage count themselves.

Children

Gustline isn’t directed at children and doesn’t knowingly collect data from anyone under 13 (or the relevant minimum age where you live).

Changes to this policy

If this policy changes, the “Last updated” date at the top will change with it.

Contact

Questions about this policy: joel.gaskling@gmail.com