What is the best app for tracking the ISS?

For pure ISS-only tracking: NASA's free Spot the Station app is excellent and single-purpose. For ISS plus Starlink, Hubble, NOAA satellites, and 10,000+ other objects — all on a real-time 3D space map with AR overlay and rocket-launch detection — LaunchDetect (https://apps.apple.com/us/app/launchdetect-space-monitor/id6762911197) is the better choice. Both are good; Spot the Station does one thing well, LaunchDetect does everything ISS-related plus much more.

Is Spot the Station free?

Yes. Spot the Station is the free official NASA app for ISS pass prediction. LaunchDetect's free tier also shows the ISS and predicts visible passes via Tonight's Sky (Silver tier $4.99/mo for push alerts and detailed predictions, Gold $9.99/mo for AR replay).

Does LaunchDetect predict ISS visible passes from my location?

Yes. The Tonight's Sky feature (Silver tier) predicts every visible ISS pass from your exact location with countdown timer, start/end times, peak elevation, magnitude prediction, and sky direction. AR Replay (Gold tier) lets you point your phone at the actual orbital trail in real time.

LaunchDetect vs Spot the Station.

Spot the Station is NASA's excellent free ISS-only app. LaunchDetect covers the ISS plus 10,000+ satellites plus rocket-launch detection plus AR — for users who want one app for all space activity.

TL;DR: Pick Spot the Station if you only care about the ISS and want a free, official, single-purpose tool. Pick LaunchDetect if you want ISS plus everything else.

Feature	LaunchDetect	Spot the Station
ISS pass prediction	Tonight's Sky	Best-in-class single-purpose
ISS push notifications	APNs / FCM	Yes
Other satellites (Starlink, Hubble, NOAA, GPS, Iridium)	10,000+ objects	ISS only
Rocket-launch detection	Thermal-IR, all operators	No
3D space map	Cesium globe	2D / 3D ISS-track only
AR sky overlay	Yes	No
Free tier	Live map + archive	Fully free