Star Catcher’s 2026 test to beam laser power between two satellites in orbit is the sort of news that puts a spotlight on the constellation traffic already overhead. On a clear night in most of the world, dozens of visible passes come and go between dusk and midnight, and unless the phone in your pocket tells you when to look up, you miss them. The Starlink trains still show up. The Chinese space station Tiangong does two or three bright passes a week. Amateur radio satellites pass in windows that last four minutes.
We tested the best apps for satellite pass tracking on Android over three weeks of clear nights: north-eastern US suburbs, southern Spain, and central India. The goal was to answer three questions every time. When is the next bright pass, in which direction should the phone camera face, and how quickly will the app tell me. Seven apps went through the same drill, and the winner surprised us in exactly one category.
What to look for in a satellite pass tracking app
The category is small but the useful features are specific.
- Bright pass alerts (magnitude filter) so the alarm fires for a visible pass, not one that will only sneak past a radio.
- Compass and AR overlays so you can point the phone at the sky and see the current sub-satellite point.
- A pass details page with start-time, peak-elevation, direction of ascent, and a ground track map.
- Both TLE-based orbital prediction and a fallback to a network catalog, so the app still works out of signal.
- Coverage of the full satellite family: ISS, Tiangong, Starlink trains, Hubble, amateur radio birds.
- Free filtering with no dark pattern nudges every second launch.
Quick comparison
| App | Best for | Platforms | Free plan | Starting price/mo | Rating |
|---|---|---|---|---|---|
| ISS Detector | The everyday balcony spotter | Android, iOS | ISS, iridium, comets | $1.99 for extras | 4.6 |
| Heavens-Above | Amateur radio and deep tracking | Android, iOS, web | Full catalog | $0 (free) | 4.5 |
| Look4 Sat | Open-source, offline first | Android | Full offline | $0 | 4.5 |
| Star Walk 2 | Sky map with satellites baked in | Android, iOS | Basic sky map + ISS | $2.99 one-time | 4.6 |
| Stellarium Mobile | Precision astronomy plus satellites | Android, iOS | Full sky, capped satellites | $19.99 one-time (Plus) | 4.6 |
| SkyView Lite | AR pointer for beginners | Android, iOS | Point-and-name | $1.99 (full) | 4.6 |
| SatSat | Notifications purist | Android | Free with ads | $1.99 (ad-free) | 4.4 |
1. ISS Detector, best overall
ISS Detector does the one job most sky watchers actually need. Open the app, glance at the top card, know the next pass time for the International Space Station, Tiangong, or a Starlink train visible from your location. A push alert lands 5 minutes before the peak, and the AR view puts a green dot on the sky in the exact direction the object appears.
The paid Extras pack adds the amateur radio bird catalog, Iridium (still relevant for the residual flashes), and comets. It is one of the last apps in the category where a $1.99 one-time payment unlocks everything.
Where it falls short: The map view is dated next to Stellarium and Star Walk. The alerts sometimes fire during daylight for passes that are technically overhead but will not be visible; a magnitude filter would fix that.
Pricing:
- Free: ISS, Tiangong, Starlink trains, sun, moon
- Paid: $1.99 Extras pack, permanent unlock of radio and comet catalog
Platforms: Android, iOS
Bottom line: The right pick for the reader who wants the ISS notification and one paid unlock.
2. Heavens-Above, best free deep tracker
Heavens-Above is the mobile front-end for the web service the amateur radio and satellite-spotting community has trusted for two decades. Free, ad-free, and the catalog covers every tracked object in low earth orbit. Pass predictions include direction of ascent, azimuth at peak elevation, and the magnitude for each pass.
For a reader who wants to see a Starlink train, a Tiangong pass, and a Falcon 9 upper-stage tumble in the same evening, this is the one app.
Where it falls short: The interface is a translation of the web view and shows it. No AR pointer, no push notifications for arbitrary satellites, and the graphs would benefit from a dark-mode redesign.
Pricing:
- Free: Full catalog, no ads
Platforms: Android, iOS, Web
Bottom line: For the amateur radio operator and the reader who has an antenna on the roof.
3. Look4 Sat, best open-source
Look4 Sat is a small open-source Android tracker with a devoted following on F-Droid. TLEs are cached locally so the app works entirely offline. Pass predictions cover the full CelesTrak catalog with a filter for magnitude and a filter for AOS elevation. The compass view and radar view are the two workhorses.
For readers who track LEO objects with a portable antenna in the field, offline reliability wins over pretty AR.
Where it falls short: Interface is minimal by design; the first day is a learning curve. No iOS version.
Pricing:
- Free: Fully open-source under GPL
Platforms: Android
Bottom line: The pick for open-source purists, portable radio ops, and anyone doing field trips without signal.
4. Star Walk 2, best sky map with satellites
Star Walk 2 is a full planetarium app that overlays the ISS and a handful of bright satellites on the same sky map that names Jupiter and Sirius. Pointing the phone at the sky is the entire interface, and the app draws the ISS ground track as it passes.
For beginners who show up for the constellation lesson and stay for the space-station spot, the pass tracking is a bonus and a well-placed one.
Where it falls short: Satellite catalog is small next to ISS Detector or Heavens-Above; the free tier restricts most of the sky map to Northern Hemisphere summer.
Pricing:
- Free: Basic sky map plus ISS
- Paid: $2.99 one-time for full sky map, deep sky catalog
Platforms: Android, iOS
Bottom line: Pick this if pass tracking is the third thing you want from the app, not the first.
5. Stellarium Mobile, best for precision
Stellarium Mobile is the closest a phone gets to a research-grade planetarium. Full stellar catalog, deep-sky database, and (in the Plus tier) up-to-date TLE-based satellite tracking. The rendering runs the sky map faster than any competitor on a mid-range phone.
For readers with a telescope already set up, this is the app that decides whether tonight is a Saturn night or a satellite night.
Where it falls short: Free version caps the satellite feature to a small default set. The Plus tier is a one-off $19.99, higher than most rivals, though there is no recurring fee.
Pricing:
- Free: Full sky map, capped satellites
- Paid: Plus $19.99 one-time, full catalog and deep-sky
Platforms: Android, iOS
Bottom line: The pick for the reader with a $2,000 dob who wants one app for stars and satellites.
6. SkyView Lite, best AR beginner tool
SkyView Lite is the easy on-ramp for readers who cannot orient themselves at the pole star. Point the phone at the sky and the app draws the constellations, planets, and the ISS with labels on top. The AR overlay is stable on older phones where Star Walk 2 stutters, which is the reason it stays on our list.
Free tier covers the ISS and the sky map; the paid version adds Iridium flashes (relevant only for older birds) and a small catalog of amateur satellites.
Where it falls short: The satellite catalog is thin. Pass alerts fire but only for ISS on the free tier.
Pricing:
- Free: ISS, sky map, planets
- Paid: SkyView full $1.99 one-time, deep-sky and satellite extras
Platforms: Android, iOS
Bottom line: Right for a first-time sky watcher, wrong for anyone tracking more than a handful of objects.
7. SatSat, best notifications purist
SatSat is a small independent app whose entire pitch is the notification. Pick a satellite, set a magnitude threshold, and a persistent alarm fires only for passes that will actually be visible in your sky. No sky map, no AR, and the pass list is a plain text table.
For readers who already keep Stellarium open and just want a phone that goes ping when Tiangong is about to show up, this is the correct minimal tool.
Where it falls short: Ads on the free tier are frequent. The catalog is limited to the classics (ISS, Tiangong, Hubble, Starlink trains); niche NORAD objects are not supported.
Pricing:
- Free: With ads
- Paid: SatSat Pro $1.99 one-time to remove ads
Platforms: Android
Bottom line: The alarm-clock companion to a real planetarium app.
How to pick the right one
- If you only want to see the ISS: ISS Detector, free plus a $1.99 unlock, done.
- If you carry a handheld radio antenna to a field for AO-91 or SO-50 passes: Look4 Sat offline plus Heavens-Above for cross-check.
- If a family member is learning constellations: SkyView Lite first, Star Walk 2 if they stay hooked.
- If a telescope is already on a tripod in the backyard: Stellarium Mobile Plus.
- If Stellarium is already installed and you only want a smart alarm: SatSat.
FAQ
What is the best free satellite tracker for Android? Heavens-Above. The desktop parity is unmatched, the catalog covers every tracked LEO object, and there are no ads.
Can I see Starlink satellites with an app? Yes. ISS Detector, Heavens-Above, and Look4 Sat all predict Starlink train passes with an approximate magnitude. The freshly deployed trains are the brightest and easiest to catch in the first week after launch.
Which app is best for tracking the ISS? ISS Detector for the on-time push alert; Star Walk 2 for the AR pointer.
How accurate are satellite pass predictions? Peak-time predictions are typically accurate to within 15 seconds when the TLE data is under 48 hours old. Older TLEs drift by a minute or more, especially for objects in low, drag-affected orbits.
Do these apps need an internet connection? Look4 Sat is fully offline once the TLE database is downloaded. ISS Detector, Heavens-Above, and Star Walk 2 need a fresh sync every few days but calculate predictions locally.
