ISS Detector

ISS Detector is built for watching the International Space Station and predicting satellite passes from a specific location. It suits observers who want practical timing, direction and weather context rather than a broad planetarium, with extra tracked objects reserved for Pro.

Overview

Each upcoming ISS pass is presented with a local start time, direction, highest altitude and duration. A notification arrives minutes before the pass starts, turning the prediction into a prompt to go outside instead of something you must remember. The local forecast can warn when clouds are likely to prevent a sighting, although it cannot make uncertain weather predictable. Sightings can be shared on social media.

The app says it combines information from NASA, Heavens-Above, the Minor Planet Center and yr.no. Its privacy policy says location calculations happen on the device and that precise location is not stored on the maker’s servers. It also says users can request access to or deletion of data associated with an anonymous user ID under GDPR. Google Play nevertheless says data cannot be deleted, an important discrepancy for Android users who want a straightforward removal path.

Key features

• ISS pass predictions: Start time, viewing direction, peak altitude and duration give enough context to decide whether a pass is worth arranging your evening around. This is more actionable than a bare calendar entry.
• Advance alerts: Notifications minutes before a pass reduce the risk of missing a short viewing window, particularly for casual observers who do not monitor the app continuously.
• Cloud checks: Forecast information helps explain why a predicted pass may not be visible. Treat it as planning context, not a promise of clear conditions.
• Premium object tracking: Pro adds Starlink, Hubble, rocket bodies, planets, comets and amateur radio satellites. Radio-satellite tracking includes transmitter information and Doppler-shift calculations, making the upgrade more relevant to radio enthusiasts than to someone interested only in ISS flyovers.
• Sharing: Social-media sharing makes it simple to report or invite others to a sighting, though the app’s core value remains prediction rather than community features.

Pricing

The freemium structure is clear. ISS Detector Satellite Tracker costs free, includes ads and supports in-app purchases. It covers the basic ISS-tracking use case, so it is the sensible starting point for occasional observers who can accept advertising and do not need the extended catalog.

ISS Detector Pro costs $17.99, paid once. The one-time purchase includes all extensions and removes ads. That is a straightforward fit for regular observers, users tracking several object types, and amateur-radio users who need transmitter and Doppler information. The free plan gives up those extensions and retains ads; no separate subscription or trial terms are stated.

Platforms

ISS Detector has cross-platform coverage across Android, iOS, macOS and the web. Support is provided by email at [email protected]. The privacy policy names Space-Track for orbital data, RevenueCat for subscriptions, Google Analytics and Firebase for app statistics, met.no for weather, and the Minor Planet Center for comet and celestial data. The maker says anonymous user IDs and subscription statuses are stored securely using industry-standard security measures.

Who it's for

Choose ISS Detector if your priority is knowing when to look up, where to face and whether clouds may make the attempt pointless. It is particularly well matched to beginners, families and casual stargazers who want alerts instead of a full sky-simulation tool. Pro is aimed at enthusiasts following multiple satellites or using amateur-radio data. Look elsewhere if you require a planetarium-style exploration experience, or if Google Play’s stated inability to delete data is unacceptable.

Pros and cons

• Pro: Pass entries combine timing, direction, altitude and duration, so they support an actual viewing decision.
• Pro: Alerts and local weather checks address the two easiest ways to miss a pass.
• Pro: Pro’s one-time price removes ads and unlocks a broad set of additional objects, including radio-satellite details.
• Con: The free version contains ads and does not include the premium object extensions.
• Con: Google Play says data cannot be deleted, despite the privacy policy’s GDPR deletion process for data tied to an anonymous user ID.

Alternatives

For a free browser-based experience that requires an internet connection, choose NASA Eyes; it runs on Android, iOS, Linux, macOS, the web and Windows.

Choose Celestia if you want an open-source astronomy project with mobile frontends and broad desktop platform coverage.

SkyORB is another freemium option, with a free Classic update and a 4.99 USD one-time SkyORB ∞ plan for Apple platforms.

Solar System Scope fits readers who want a free WebGL browser version alongside mobile and desktop editions.

Cosmic Watch offers free sky, Earth and solar-system views with notifications, plus paid plans.

Star Chart is free with every feature and upgrade included and no subscriptions or paywalls.

Star Chart is a separate free edition with in-app upgrades.

Stellarium is a free choice for Linux, macOS, web and Windows users.

Browse more options in Astronomy Apps.

Verdict

ISS Detector is a strong choice for anyone who wants dependable pass timing, a last-minute alert and a local cloud check in one focused app. Buy Pro if you will track more than the ISS or want an ad-free experience; choose another astronomy tool if you need deeper sky exploration or cannot accept Google Play’s data-deletion limitation.