Comparison

AstroTool vs SkySync

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

Head to head
About

AstroTool

Features
Read full description

AstroTool — Astrophotography Planner & Sky Map Plan better. Shoot more. Miss nothing. AstroTool is the complete astrophotography companion for iPhone — 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 — 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 — ONE-TIME UNLOCK Planner Everything you need before you head out. Moon phase and illumination with an imaging impact rating. Full twilight schedule — 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 — 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. — 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.

About

SkySync

This app helps you discover and track celestial events like meteor showers and eclipses. It provides countdown timers and customizable notifications so you never miss an opportunity to stargaze. It also features a dark sky finder to locate optimal viewing spots.

Highlights
  • Event calendar (meteor showers, eclipses, moons, comets)
  • Countdown timers to events
  • Customizable notifications
  • Dark sky finder with Bortle scale
  • Minimalist nighttime design
  • No account required
Features
Read full description

SkySync tracks upcoming cosmic events and alerts you before they happen — so you're always ready to look up. Features: * Full event calendar: meteor showers, eclipses, full & new moons, comets, planet oppositions, and satellites * Countdown timers to every upcoming event * Custom notifications — get alerted 1 hour, 1 day, 3 days, or 1 week ahead * Dark sky finder — locate the best stargazing spots near you with Bortle scale ratings * Clean, minimal design built for nighttime use No account required. No ads. Just the sky.

Screenshots

AstroTool4 screens
SkySync4 screens

Verdict

The call

The clearest difference is in-app purchases: SkySync at none against AstroTool's 1. SkySync also leads on iOS requirement (15.1 vs 17.0). On price, update cadence, ads and device support 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

CostPrice · In-app purchases · Ads · Monetization

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

UpkeepUpdate frequency

AstroTool ships an update every 9 days, SkySync weekly. The most recent releases landed on October 7, 2026 and October 31, 2026 respectively.

Scorecard2 real differences · 7 level
AstroTool versus SkySync: the parameters behind the verdict, then further details
ParameterAstroToolSkySync
PriceFreeFree
Rating—5.0 (4 ratings) — better
Number of ratings—4 — better
Update frequencyEvery 9 daysWeekly — better
AdsNoNo
In-app purchasesYesNo — better
Monetization—Free
DevicesiPhone, iPadiPhone, iPod
Requires iOS17.015.1 — better
Further details — not scored
Size3 MB24 MB
Age rating4+4+
Developerluciano cavazosKAHLESON MILES BLANCHARD

In-app purchases

1 purchases

AstroTool

One-time1
  • AstroTool Premium Unlock$4.99
None

SkySync

No in-app purchases

Questions

Is AstroTool free?
AstroTool is free to download, with in-app purchases available.
Is SkySync free?
SkySync is free to download, with no in-app purchases.
Do AstroTool or SkySync have ads?
Neither AstroTool nor SkySync shows ads.
Which is updated more often, AstroTool or SkySync?
AstroTool ships an update every 9 days, and SkySync weekly. Most recently, AstroTool was updated on October 7, 2026 and SkySync on October 31, 2026.

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