Space Station Alarm

The space station is the third-brightest thing in the sky — when it passes high over you, this wakes you a minute before, and points you the right way.

Space Station Alarm wakes you a minute before a crewed space station climbs high enough over your location to be worth walking outside for — then shows you exactly where to look.

The International Space Station and China's Tiangong are among the brightest things in the night sky, brighter than any star. But most passes are too low, too dim, or happen in daylight when nothing is visible. This app quietly ignores all of those and alerts you only for the ones actually worth seeing: high, dark-sky, sunlit passes.

• One alarm, a minute before the station clears the rooftops — not as it scrapes the horizon, and not once it's already overhead. • A live compass marker. Hold up your phone, or raise your wrist, and a glowing dot rides a dial, pointing at the real spot in the sky. Turn until it's at the top and look up. • The station's height and bearing, updating every second as it crosses. • Works on Apple Watch, alone — the alarm rings and the dial points even when your phone is in another room. • No account, no ads, no subscription. One screen. Buy it once.

How it works: your phone fetches the stations' orbits, works out every visible pass for the next 30 days, and hands them to the system as alarms — so they fire whether or not the app is running. Nothing is tracked; your location never leaves your device.

Passes come in clusters — a run of clear evenings, then two or three weeks of nothing — so the month-long view answers the real question during the quiet weeks: when is the next one?

Independent app. Not affiliated with NASA, ESA, Roscosmos, or CMSA. Orbital data courtesy of CelesTrak.