ISS Tracker vs HamSat
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
ISS Tracker
Monitor the International Space Station's live position and vital telemetry data in real-time. Track its orbit, altitude, velocity, and internal environmental systems. Ideal for space enthusiasts and students interested in space exploration.
- Real-time ISS position tracking
- Interactive world map
- Altitude and velocity data
- Comprehensive telemetry monitoring
- Environmental and power system data
- Dark mode support
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Find out when the International Space Station flies over you and exactly where to look. On a good night it’s brighter than any star. YOUR NEXT PASS, IN PLAIN WORDS “Tonight at 8:05 PM. Look west, low.” Each pass also says how long it’s visible and how bright it is, and has a round sky chart that shows its path, from where it appears to where it fades. See 14 days of passes, and the cloud forecast for the next ones. ALERTS FOR GOOD PASSES Get a heads-up a few hours before a good pass, and an alert 5 minutes before it starts. A good pass climbs at least 30° above the horizon, or is bright and long. If two weeks have none, you get alerts for the best low passes instead. You can turn on alerts for every visible pass in the app’s settings. A Live Activity counts down on your Lock Screen and in the Dynamic Island. FIND IT IN THE SKY Hold your phone up and follow the pointer to the station. Saw a bright, moving light? Ask “Was that the ISS?” and get a straight answer. No telescope needed. WHERE IS THE ISS RIGHT NOW? See it on a 3D globe, with the day and night sides of Earth, or on a live map with the ground track of its orbit. You can add Tiangong, China’s space station, and get its passes too. WHO’S UP THERE See the crew on board, and the next launches, dockings and spacewalks. ALWAYS ONE GLANCE AWAY Widgets show your next pass on the Home Screen and Lock Screen. A Control Center button opens the sky pointer. PRIVATE AND SIMPLE No account needed. Every pass is worked out on your phone, and your exact location is never sent to us. Apple Weather and Apple Maps use it for the cloud forecast and the place name. For iPhone and iPad.
HamSat
Track satellite passes with real-time azimuth, elevation, and Doppler-corrected frequencies. Features an Apple Watch companion for wrist-based aiming and pass tracking, and allows users to stamp photos with operational data.
- Apple Watch companion for pass tracking and antenna aiming
- Live sky dome with real-time satellite arcs
- Aim mode with phone compass and haptic feedback
- Doppler-corrected frequencies for operating during passes
- Photo stamping with callsign, grid, satellite, and UTC time
- Offline satellite tracking and propagation
- Geostationary satellite tracking
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HamSat is the satellite tracker built for amateur radio operators — with an Apple Watch companion on your wrist and, new in 2.1, a sked planner that finds the passes you and another operator can work together. NEW — SKED PLANNER (Pro) • Plan a contact, not just a pass: enter another operator's grid square and find every window where a satellite sees you both • Set a minimum elevation for each end of the link — a window only counts if it's workable at both stations • One tap adds the sked to your calendar with the overlap times, a 10-minute reminder, and the radio setup PLAN AHEAD • Pass predictions up to 7 days out • Add any pass to Apple Calendar — times, reminder, and frequencies in the notes. HamSat never reads your calendar. • Choose your pass-alert tone — including a CW "HI" in Morse APPLE WATCH (Pro) • Your next favorite pass on your wrist: live azimuth, elevation, Doppler-corrected frequencies, and a countdown to AOS • Guided wrist-aim — follow an arrow straight to the satellite and feel a haptic tap the instant you're locked on. Aim your antenna without looking at a screen, hands free for the radio. • Propagated on the watch itself, so it keeps tracking even when your phone is out of range PASS TRACKING • Live sky dome with the satellite's arc and a glyph riding it in real time • Fullscreen Live tracker — big AZ/EL, Doppler-corrected frequencies, landscape split-pane • Aim mode uses your phone's compass to show where you're pointing — no forced figure-8 calibration, just point and go • Apple Maps ground track with horizon footprint OPERATING DURING A PASS • Doppler-corrected RX (and TX for SSB/linear) dial frequencies, updated every second • 10-minute and AOS notifications that deep-link straight to the pass • Live Activity + Dynamic Island on the lock screen, elevation and azimuth ticking live • Bell badge on any pass you've set an alert for ROVER PROOF PHOTOS • Stamp a photo at your site with your callsign, grid, satellite, and UTC time — proof of where you were on the air • Fresh photo or one from your library; share to X, Messages, AirDrop — or submit for the AMSAT Rover Award ALWAYS OVERHEAD (free) • Lists any geostationary satellite in your sky — QO-100 (Es'hail 2) for Europe, Africa, and the Middle East • "Find it in the sky" — point your phone and check your line-of-sight to the bird is clear • No Pro required for geostationary satellites SATELLITE CATALOG • Friendly designations everywhere — SO-50, AO-91, RS-44, JO-97 — with launch names as subtitles • Search by name or NORAD ID • Curated radio data for the most-worked birds, plus live SatNOGS for the long tail — kept fresh by HamSat's catalog service • Filter by mode (FM, linear, beacon, data, telemetry) ACCURATE & OFFLINE • Full SGP4 propagation on-device — the model the pros use, so times and positions match apps like ISS Detector • Works completely offline — every pass, sky dome, ground track, and Doppler computed locally. No API keys, no rate limits. • Always-fresh orbital data via HamSat's catalog service, with direct CelesTrak/AMSAT fallback — or pin a source • Settings shows how fresh your orbital data is PRIVACY-FIRST • Your location stays on-device — nothing about you is sent to any server • Orbital data from public sources (CelesTrak, AMSAT, SatNOGS) • No accounts, no tracking, no ads HamSat Pro — the field operator's toolkit • Sked planner — mutual passes with any partner grid • Apple Watch tracking & guided wrist-aim • Fullscreen Live tracker with second-by-second Doppler (landscape split-pane) • Live in-pass Doppler — corrected RX/TX at AOS, max, and LOS • Overhead-now live tracker for your favorites • Unlimited scheduled alerts — not just three • Shareable Rover proof photos One-time purchase, no subscription. 73 — and good DX!
Screenshots
Verdict
The clearest difference is in-app purchases: ISS Tracker at none against HamSat's 1. ISS Tracker also leads on review sentiment (100% vs 67%) and rating (4.7 vs 4.4). HamSat's advantage is update cadence (every 2 days vs weekly). On price, ads, device support and iOS requirement there is nothing between them.
Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS
Both are free to download. HamSat sells 1 one-off in-app purchase. ISS Tracker asks for nothing beyond the download.
ISS Tracker holds the better App Store score, 4.7 against 4.4. Both are backed by a comparable volume of ratings — 19 and 5 respectively. Written reviews point the same way: 100% of ISS Tracker's written reviews are positive against 67% of HamSat's.
ISS Tracker ships an update weekly, HamSat every 2 days. The most recent releases landed on October 24, 2026 and October 25, 2026 respectively.
| Parameter | ISS Tracker | HamSat |
|---|---|---|
| Price | Free | Free |
| Rating | 4.7 (19 ratings) — better | 4.4 (5 ratings) |
| Positive reviews | 100.0% of reviews — better | 66.7% of reviews |
| Number of ratings | 19 — better | 5 |
| Update frequency | Weekly | Every 2 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad | iPhone, iPad, Apple Watch — better |
| Requires iOS | 26.0 — better | 26.4 |
| Further details — not scored | ||
| Size | 15 MB | 11 MB |
| Age rating | 4+ | 4+ |
| Developer | Lucent Enterprises Ltd. | Vasco Barreiros |
Customer experience
ISS Tracker
HamSat
In-app purchases
ISS Tracker
No in-app purchases
HamSat
- HamSat Pro$9.99








