Sunfold

Golden hour, blue hour, sunrise and sunset for anywhere on Earth. Computed on your phone from the real astronomy, so it works with no signal and no account.

Sunfold gives you the times for golden hour, blue hour, sunrise and sunset, where you're standing and in any city you save. It does the astronomy on your phone, from your coordinates, so there's nothing to fetch and nothing to sign into.

The angles are the ones photographers work to. Golden hour is the sun between 6° above the horizon and 4° below it; blue hour runs from 4° below down to 6°. Sunfold recomputes both every time you open it, which is why it still works with no bars.

FEATURES

• A countdown to whatever the sun does next, with the day laid out under it in order, first light through to last • Drag the scrubber to put the sun anywhere in the day and watch its position move against the sky, from yesterday out to six days ahead • Day length, day by day, for the fortnight ahead • Twelve months of dates worth knowing: both equinoxes, both solstices, your earliest and latest sunrise, your earliest and latest sunset, and the clock change if your zone has one • Save as many cities as you like, each on its own time zone, so Tokyo's sunrise reads on Tokyo's clock while you're sitting in Paris • Twelve cities built in and usable offline: Cape Town, Dubai, London, Los Angeles, New York, Paris, Reykjavík, Rio de Janeiro, Singapore, Sydney, Tokyo, Tromsø • Twilight events you can switch off, and times in 12- or 24-hour

Far enough north or south, at the right time of year, some of these events genuinely don't happen. Tromsø in December has no sunrise, and Sunfold shows nothing for it rather than a plausible-looking time for something that isn't going to occur.

No account, no sign-in, no analytics, no ads, no advertising identifier, no third-party SDKs, no servers. Your saved cities and settings sit in the app's own storage on the device and go nowhere else. Coordinates and whatever you type into city search go to Apple's geocoder, part of iOS, to turn a position into a place name; that's the only thing that leaves the phone.

These are geometric times, not a forecast. Sunfold knows when the sun reaches the angle, not whether there'll be cloud in front of it.