Comparison

SQM Mobile vs AstroTool

Price, ratings, monetisation and update history for both apps, side by side โ€” with what reviewers say about each.

Head to head
About

SQM Mobile

Features
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Bring all your sky quality measurements together in one place. SQM Mobile is the ideal companion for handheld Sky Quality Meters, automatically synchronizing field measurements with SQM Toolbox on your Mac. It also imports measurements exported from Dark Sky Meter Pro, making it easy to build a single long-term archive of all your observations. KEY FEATURES Field-Ready Data Collection * Quick and easy measurement entry for handheld SQM devices * Manual entry of measurements from Dark Sky Meter * Automatic GPS location recording for each measurement * Timestamp for accurate astronomical correlation * Offline measurement storage โ€“ sync whenever a connection becomes available * Bubble level for accurate zenith pointing * Import measurements exported from Dark Sky Meter Pro Smart Location Features * Automatic GPS coordinate capture * Manual location override (to define local sky-background conditions during site surveys) * Perfect for camping trips, dark-sky site surveys and travel observations Automatic Cloud Sync * Seamlessly sync measurements to SQM Toolbox on your Mac via iCloud * Private, secure storage โ€“ only you can access your measurements * Works anywhere with an internet connection โ€“ no complex setup required * Real-time synchronization across all your Apple devices Quick Analysis * Instant Bortle classification for every measurement * On-device light pollution assessment * Comparison with natural sky-background brightness * Simple graphical display including twilight conditions * Measurement validation and quality indicators * Clean, intuitive interface designed for field use Astronomical Context * Automatic twilight condition detection * Moon phase information for every measurement * Sun elevation calculations Simple and Reliable * Designed for easy use in the dark * Large, clear controls for nighttime operation * No account setup required โ€“ simply use your existing iCloud account Perfect for * Amateur astronomers and citizen scientists carrying out site surveys * Researchers monitoring light pollution * Dark-sky organizations documenting observing conditions * Anyone using handheld SQM instruments or Dark Sky Meter who wants long-term storage, synchronization and analysis of their measurements Requires: iOS 17.0 or later, iCloud account Works with: Unihedron Sky Quality Meter (SQM, SQM-L), Dark Sky Meter Pro imports, and manual entry from Dark Sky Meter. Companion to: SQM Toolbox for macOS (available separately)

About

AstroTool

Features
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AstroTool โ€” Astrophotography Planner & Sky Map Plan better. Shoot more. Miss nothing. AstroTool is the complete astrophotography companion for iPhone โ€” from scouting tonight's targets to logging every capture. A live sky map you can actually use in the field, planning tools built around how astrophotographers think, and a session logger that keeps your imaging history in one place. FREE FEATURES Sky Map A fully rendered live sky chart with 100+ bright stars, all 110 Messier objects, the Sun, Moon, and all planets. Constellation lines, constellation name labels, the Milky Way band, and the ecliptic arc are all drawn in real time. Tap any object for instant identification โ€” name, type, magnitude, and position. Procedural rolling-hill horizon with compass ticks and cardinal labels. Motion-driven so the sky moves as you move. Deep Sky Catalog Browse the complete Messier catalog with search, type filters, and sort by ID, magnitude, or altitude. Every object shows rise, transit, and set times for your location, a visibility chart for tonight, and your full capture history for that target. Mark favorites and pick up right where you left off. PREMIUM โ€” ONE-TIME UNLOCK Planner Everything you need before you head out. Moon phase and illumination with an imaging impact rating. Full twilight schedule โ€” civil, nautical, and astronomical dusk and dawn with total dark-sky hours. All visible planets with live altitude and transit times. Jupiter's Galilean moons in a live canvas diagram. Best targets tonight ranked by a composite altitude and moon-separation score. Target schedule to plan your imaging windows object by object. Astrophotography Calculator Field of view for your exact sensor and focal length with sensor presets for Full Frame, APS-C, Micro 4/3, and custom. Unguided exposure limits via the 500, 400, and 300 rules for fixed tripod, tracking mount, and guided setups. Integration time calculator with sub count and a signal quality indicator. Session Logger Log every observing session with sky conditions โ€” Bortle scale, seeing, and transparency. Add individual captures with exposure length, sub count, gain, filter, equipment, reference path, and a star rating. Total integration time tracked automatically. Export any session as formatted text to share or archive. Full equipment manager for telescopes and cameras with sensor specs, focal length, and reducer support. Target Schedule Build a nightly imaging plan by scheduling capture windows for specific catalog objects. Log past captures directly from the schedule. Mark targets done as you work through the night. Events & Alerts Upcoming meteor showers with ZHR and peak dates, lunar phases, planet oppositions and conjunctions, greatest elongations, and solstices and equinoxes. Notification support so you never miss an event. Polar Alignment Guide & Pre-Session Checklist Step-by-step polar alignment instructions and a fully customisable pre-session checklist with presets covering setup, camera, focusing, guiding, imaging, calibration, and wrap-up. โ€” No subscription. No ads. No account required. Pay once, own everything forever. All calculations run on-device using your GPS location. No data is sent anywhere.

Screenshots

SQM Mobile4 screens
AstroTool4 screens

Verdict

The call

The clearest difference is in-app purchases: SQM Mobile at none against AstroTool's 1. AstroTool's advantage is update cadence (every 9 days vs every 4 weeks). On price, ads, device support and iOS requirement there is nothing between them.

Scored on Price ยท Rating ยท Positive reviews ยท Number of ratings ยท Update frequency ยท Ads ยท In-app purchases ยท Monetization ยท Best chart rank ยท Devices ยท Requires iOS

CostPrice ยท In-app purchases ยท Ads ยท Monetization

Both are free to download. AstroTool sells 1 one-off in-app purchase. SQM Mobile asks for nothing beyond the download.

UpkeepUpdate frequency

SQM Mobile ships an update every 4 weeks, AstroTool every 9 days. The most recent releases landed on November 5, 2026 and October 31, 2026 respectively.

Scorecard2 real differences ยท 4 level
SQM Mobile versus AstroTool: the parameters behind the verdict, then further details
ParameterSQM MobileAstroTool
PriceFreeFree
Update frequencyEvery 4 weeksEvery 9 days โ€” better
AdsNoNo
In-app purchasesNo โ€” betterYes
DevicesiPhoneiPhone, iPad โ€” better
Requires iOS17.617.0 โ€” better
Further details โ€” not scored
Size42 MB3 MB
Age rating4+4+
DeveloperGerSpatialluciano cavazos

In-app purchases

None

SQM Mobile

No in-app purchases

1 purchases

AstroTool

One-time1
  • AstroTool Premium Unlock$4.99

Questions

Is SQM Mobile free?
SQM Mobile is free to download, with no in-app purchases.
Is AstroTool free?
AstroTool is free to download, with in-app purchases available.
Do SQM Mobile or AstroTool have ads?
Neither SQM Mobile nor AstroTool shows ads.
Which is updated more often, SQM Mobile or AstroTool?
SQM Mobile ships an update every 4 weeks, and AstroTool every 9 days. Most recently, SQM Mobile was updated on November 5, 2026 and AstroTool on October 31, 2026.

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