Heavens-Above vs ISS Detector

Heavens-Above provides satellite predictions and sky information through Android, iOS and web access. The website lists 10-day predictions for selected satellites, daily predictions for brighter satellites and Starlink passes from a launch. It also offers a live sky view, interactive sky chart, dynamic 3D Starlink orbit display and interactive 3D ISS visualization. Charts and information cover the Sun, Moon, planets, comets, asteroids and constellations. The Android app includes predictions for the ISS, visible satellites and radio satellites, plus orbit and ground-track views, night mode and an orientation-based tracker. Selected passes can be added to a device calendar. Predictions run locally, with a data connection needed every few days. The free plan costs nothing; Heavens-Above Pro costs $4.99, paid once and removes Android adverts. Predictions become less accurate farther from the current date.

ISS Detector helps users find visible International Space Station passes and predict satellite passes for their location. For each upcoming ISS pass, it gives the local start time, direction, highest altitude, and duration, and can notify users minutes before the pass begins. It checks the local forecast and indicates when clouds may prevent a sighting. Premium features add tracking for Starlink, Hubble, rocket bodies, planets, comets, and amateur radio satellites; amateur radio tracking includes transmitter information and Doppler shift calculations. Users can share sightings on social media. ISS Detector says it combines information from NASA, Heavens-Above, the Minor Planet Center, and yr.no weather. It is listed for Android, iOS, macOS, and web. The free plan includes ads and in-app purchases; ISS Detector Pro costs $17.99, paid once and includes all extensions with no ads. Its privacy policy says location calculations happen on-device and precise location is not stored on the maker’s servers. Google Play says data can’t be deleted.