Skyglim: Aurora Forecast. Last updated: November 1, 2026.
This policy explains what data the Skyglim app ("the app") collects and why. The app is published by Mehmet Yüksel Polat ("we").
No account, no ads
The app has no sign-up and shows no ads. Your saved places and settings are stored only on your device.
Location
If you allow location access, the app uses your location on your device to calculate the aurora chance, darkness and moonlight where you are. To get the hourly cloud forecast, the app sends your coordinates to Apple WeatherKit (and, only if Apple Weather is unavailable while you use the app, a position rounded to about 1 km to the Norwegian Meteorological Institute, MET Norway). The forecast never sends your location to our servers or stores it. You can use the app without location access by choosing a city.
Sighting reports
Only if you tap "I see it now", the app sends a sighting report to our Google Cloud Firestore database in the EU (europe-west1): your area rounded to 0.1 degrees (about 10 km), the brightness you chose (faint, visible or strong), the time, and a random anonymous Firebase ID that is not linked to your name, email or Apple ID. Other app users see reports within 150 km as a count and distance, never an exact position or ID. Reports are deleted automatically after 24 hours. Legal basis: your action (consent, GDPR Art. 6(1)(a)); you can simply stop reporting. To ask for earlier deletion, email us.
Magnetometer data
If you are in or near Finland, the app downloads public magnetometer readings from the Finnish Meteorological Institute (FMI, CC BY 4.0). No personal data is sent to FMI beyond the technical request (IP address) that every internet download needs.
Alerts
Alerts are created on your device. If you turn on alerts, the app may also subscribe your device to a coarse alert channel through Google Firebase Cloud Messaging, for example "northern band 60 to 65, longitude 0 to 30 degrees". That channel covers a very large area and does not reveal your location. Firebase receives a push token for your device to deliver these alerts.
Data we collect
Usage data (analytics). We use Google Firebase Analytics to see how the app is used, for example which screens are opened and which features are used, plus your optional onboarding answers. Firebase uses an app instance ID and estimates an approximate location (country or city level) from a masked IP address.
Crash reports. Firebase Crashlytics collects crash logs and device model to help us fix bugs.
Purchase data. Apple processes all payments. We use RevenueCat to check whether you have an active subscription. RevenueCat receives your purchase history and an anonymous app user ID. If you installed the app from an Apple Search Ads ad, RevenueCat may receive Apple's ad attribution token so we can measure the ad.
Ad measurement. The app uses Apple's SKAdNetwork, which reports installs and purchases to ad networks in aggregate. The app includes the Meta (Facebook) SDK to measure app installs from Meta ads. Only if you allow tracking in the iOS prompt, the advertising identifier (IDFA) is shared with Meta and RevenueCat for ad measurement. If you decline, it is not collected. Purchases are reported to Meta by RevenueCat's server, not by the app.
Data we do not collect
We do not collect your name, email address, contacts or photos.
We share data with these providers only for the purposes described in this policy. Each provider must protect it to the same or an equal standard as this policy.
Data retention and deletion
Deleting the app removes your saved places and settings. To ask us to delete analytics or purchase records linked to your anonymous ID, email us at betgesoftware+aurora@gmail.com.
Children
The app is not directed at children under 13, and we do not knowingly collect personal information from children.
Changes
If we change this policy, we will update this page and the date above.