Bluehour: Twilight Cities

Bluehour brings you a single beautiful city skyline every day, photographed during the blue hour — the brief stretch of twilight when the sky turns deep luminous blue and the city lights begin to come on. It is the most photogenic time in any city, and it now has a quiet daily home on your phone.

Each morning a new skyline arrives. You open the app and see Singapore tonight, or Reykjavík at dawn, or Doha glowing across the bay. A short note tells you the tallest building, the year it was completed, the photographer who captured the shot. Save it, share it, or set it as your wallpaper.

Beyond the daily skyline, Bluehour has a living atlas of cities. Tap the map and land anywhere — Mumbai at dusk, Toronto at twilight, Cape Town in the soft glow before sunrise. Browse by continent, by tallest building, by what you have already seen. Your collection grows quietly as you wander.

The most unusual part of Bluehour is the Twilight Now tab. The blue hour is happening somewhere on Earth at every moment of the day. Sun positions are computed precisely from your device clock and the chosen cities, then the app shows you exactly which ones are in blue hour, golden hour, or pre-dawn light right at this second, with a countdown of how long that light will last. Open the app at lunchtime to catch Sydney winding down its evening blue hour. Open after dinner to watch Reykjavík just entering its long winter twilight. A small live signal from cities across the world.

Save a skyline and it lands in your personal gallery. The wallpaper rotation, if you turn it on, quietly drops a new view from your collection into your Photos library each morning so you can refresh your lock screen with a tap.

Bluehour is a quiet companion. A new skyline waiting whenever you happen to look.