Support

Check three things in order. First, the notification permission in your phone's system settings. Second, turn battery optimisation off for AstroTools: Android puts background apps to sleep, and that is by far the most common cause. Third, open the notification section in the app and make sure the type you expect is enabled and its threshold is not set too high.

Clear-night notifications fire when the night score rises above your threshold. If the threshold is 70 and the night scored 65, nothing is sent even under a clear sky — the score also weighs the Moon, humidity and wind at altitude. Lower the threshold in the notification settings.

Grant location access in the "while using the app" mode and check that location services are switched on system-wide. If detection still fails, or you are planning a trip, you can set the point by hand — by searching for a place or tapping the map.

An ordinary forecast answers "do I need an umbrella" and describes the day. Astro-weather describes the night and different parameters: cloud cover split into low, mid and high layers, the dew point, the wind at 120 m. You can also switch between the ECMWF and DWD ICON models — when they disagree, that itself tells you how reliable the forecast is.

The score weighs more than clouds. A bright Moon washes the sky out, and the longer it stays above the horizon the more the score drops. The second factor is darkness: during twilight and white nights the score falls even with no clouds at all. The full algorithm is described on the About page.

Pull the screen down to force a refresh. The forecast updates together with its source, usually a few times a day, so asking more often gains nothing.

No. Every tool works without registration, in guest mode. An account is only needed if you want your settings and saved places synced between devices.

The profile screen has a delete-account button; it removes the account together with the data attached to it. The action cannot be undone. Settings kept in guest mode live only on the device itself.

Partly. Light pollution map tiles you have already viewed are cached and open without a connection, as does the last forecast you loaded. Refreshing the forecast, viewing solar imagery or panning to new parts of the map does need the internet.

Write through the form below and include the point on the map, the date and what exactly does not add up. Every calculation is open and documented on the About page, so discrepancies are almost always traceable.