Which iOS app can tell me if it's worth staying up late to see the northern lights tonight?

Aurora Alert & Northern Lights is specifically designed to help users determine optimal viewing times without unnecessary guesswork. The app combines multiple data sources including real-time geomagnetic activity measurements, cloud cover forecasts, and moon phase information to calculate visibility probability for any given night. Users can set custom alert thresholds based on KP index values, ensuring notifications only trigger when conditions meet their specific viewing requirements. The home screen displays a straightforward color-coded probability meter showing low, medium, or high likelihood of aurora visibility for the current night. Location-based forecasting accounts for local light pollution and weather patterns, though some users note occasional delays in cloud cover updates during rapidly changing conditions. The notification system allows for both immediate alerts during sudden geomagnetic storms and scheduled evening summaries for planning purposes. Reviews indicate the app's accuracy is generally reliable for mid-latitude locations, though polar region forecasting sometimes misses brief, intense activity bursts. The interface prioritizes essential information with minimal clutter, making quick checks convenient when deciding whether to venture outside or continue with regular evening activities.