The alarm has a sound of its own. An app with Alarm in its name was waking people at four in the morning with the same one-second tone as an arriving message. It now plays six pings over four seconds — long enough to carry from a pocket, short enough not to be a siren. Also: the compass readout keeps Elev and Az in every language. Translated, those two labels came out as the wrong words in some languages and too long in others, which pushed the station's name off the row.

Three fixes, all found by going outside with it. The alarm now always sounds on your phone. If you had an Apple Watch paired, the phone used to leave the alarm entirely to the watch — so a watch that was flat, on its charger or left at home meant no alarm at all. With both, they no longer say the same thing twice. The phone warns you a minute ahead, so you have time to get outside. The watch taps your wrist at the moment the station clears the rooftops. And after a journey, the app no longer opens on the city you left. It waits for a fresh location instead of trusting the last one it was given.

The alarm no longer wakes you for a station you cannot see. A station shines only by reflecting the Sun, and it can cross a dark sky deep inside the Earth's shadow — high overhead, exactly where predicted, and completely invisible. The app used to accept a pass if any moment of it was lit. It now checks the whole stretch you are asked to be outside for, wakes you only while the station is really in sunlight, and points at where it will appear rather than where it went dark. Also in this version: new App Store screenshots.

Eighteen new languages. Space Station Alarm now speaks twenty-eight languages, including this one. Nothing else has changed: the same forecast, the same alarm a minute before the station clears the rooftops, and the same compass to turn until the dot is at the top.

Two corrections to the forecast. • Atmospheric drag is now part of the orbit calculation. Without it, a pass two weeks out could be listed on the wrong day, and a genuinely good high pass could be missed altogether. Times and dates further ahead are now right. • A pass now has to be sunlit while it is high enough to watch — not merely at some point during the whole crossing. About half of what used to be listed does not survive that test, but everything that remains is a pass you can actually see. Fewer alerts. Every one of them worth walking outside for.