Comparison

Celestial Nav vs VoyLog

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

Head to head
About

Celestial Nav

This app provides tools for celestial navigation, offering computations for celestial bodies and sight reductions. It includes an offline perpetual almanac and allows for quick capture of observation data for accurate course adjustments.

Highlights
  • Celestial navigational computations
  • Offline perpetual almanac
  • Quick celestial observation data capture
  • High accuracy sight reductions
  • Sight planning and reduction tools
  • Celestial fix computations
Features
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We believe celestial navigation is an amazing skill and develop Celestial Nav to offer a simple, yet powerful and all encompassing app for our users. Celestial Nav is an easy to use, all-in-one tool which offers: • Celestial navigational computations for your device • Simple toolbar menu for quick access • Internally stored perpetual Almanac • Offline ready and functional without the need for other external tools • Quick and easy capture celestial observation data • High accuracy sight reductions • Star reference tables SIGHT PLANNING • Local Hour Angle (LHA) for Aries • Star tables sorted by name, magnitude, declination, and SHA • Sunrise, sunset, twilight, and location reference • Moon phase reference SIGHT REDUCTION • High accuracy sight reduction algorithm • Perpetual Almanac offering accurate data for years 1600 - 3000 • Almanac data for Sun, Moon, Mercury, Venus, Mars, Jupiter, Saturn • Detailed Almanac data for 58 navigational stars • Assumed Position (AP) for any user defined position • Line of Position (LOP) intercept data for accurate course and speed adjustments • Computational variables displayed for accuracy and validation CELESTIAL FIX • Computations by USNO algorithm in the Nautical Almanac • Save all your LOP in an easy reference table BASIC VERSION Free daytime celestial navigation tools using the sun: • Unlimited sextant sight reduction calculations • Sight reduction to a line of position using the sun • Perpetual almanac for the sun • Advanced sight corrections for index error, eye height, temperature, and pressure • Support for upper and lower limb reference • Star Table with navigational references • Detailed Sun references • Limited Moon references PRO FEATURES (IN-APP PURCHASE) Advanced Day & Night Celestial Navigation includes all BASIC features plus: • Almanac data for 65 navigational bodies for years 1600 through 3000 • Map display for saved LOPs • View intercepts with course and speed corrections • Metric and imperial unit support with automatic conversions • Support for coordinate entries in different formats (H° M’ S” or Decimals) • Save all your LOP calculations for future reference • Save user preferences and settings • Unrestricted moon references • Almanac and algorithmic models for 65 navigational bodies: • Sun, Moon, Mercury, Venus, Mars, Jupiter, and Saturn • 58 navigational stars Supported stars: Acamar, Achernar, Acrux, Adhara, Aldebaran, Alioth, Alkaid, Alnair, Alnilam, Alphard, Alphecca, Alpheratz, Altair, Ankaa, Antares, Arcturus, Atria, Avior, Bellatrix, Betelgeuse, Canopus, Capella, Deneb, Denebola, Diphda, Dubhe, Elnath, Eltanin, Enif, Fomalhaut, Gacrux, Gienah, Hadar, Hamal, Kaus Australis, Kochab, Markab, Menkar, Menkent, Miaplacidus, Mirfak, Nunki, Peacock, Polaris, Pollux, Procyon, Rasalhague, Regulus, Rigel, Rigil Kent., Sabik, Schedar, Shaula, Sirius, Spica, Suhail, Vega, Zubengenubi REFERENCES Sight reductions and celestial calculations use various internationally accepted references for the most accurate results: • Jean Meeus - Astronomical Algorithms • US Naval Observatory (USNO) Almanac and Algorithms • Hipparcos New Astrometric Catalog, Published 2007 • ELP2000-85 SUBSCRIPTION TERMS Celestial Nav is free to download and the basic features free to use. A paid upgrade to the PRO version provides access to premium features and additional tools. We may offer trial subscriptions that give limited time access to all PRO features and premium content for the duration of the trial period. Trial subscriptions automatically expire and the app will revert back to the Basic version thereafter. No data is lost but access and use of premium features will no longer be available.

About

VoyLog

Features
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VoyLog is the fastest way for ship captains and officers to create professional voyage log emails. Fill a simple form with position, time, bunkers, cargo, drafts and ETA — and VoyLog builds a clean, office-ready report you can send from your own mail app in seconds. No typing long reports, no formatting mistakes. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://trmyindustry.com/voylog-privacy.html FEATURES • Create a complete voyage report in about 30 seconds • Auto-fill your vessel's position with GPS • Track positions, routes, fuel, cargo, drafts and ETAs • The Lane: follow your vessels on a live marine map, built from the reports you send • Analytics: turn your reports into voyage insights, all in one place • Clean, professional emails ready to send VoyLog is completely free to use. Upgrade to VoyLog Pro for advanced analytics and more.

Screenshots

Celestial Nav4 screens
VoyLog4 screens

Verdict

The call

The clearest difference is update cadence: VoyLog at every 4 days against Celestial Nav's every 3 weeks. On price, ads, in-app purchases 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. Celestial Nav sells 6 in-app purchases, starting at $1.99 per month and VoyLog sells 1 in-app purchase, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

Celestial Nav ships an update every 3 weeks, VoyLog every 4 days. The most recent releases landed on October 1, 2026 and September 26, 2026 respectively.

Scorecard1 real difference · 9 level
Celestial Nav versus VoyLog: the parameters behind the verdict, then further details
ParameterCelestial NavVoyLog
PriceFreeFree
Rating4.3 (10 ratings) — better—
Positive reviews64.3% of reviews—
Number of ratings10 — better—
Update frequencyEvery 3 weeksEvery 4 days — better
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases—
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.015.0
Further details — not scored
Size20 MB56 MB
Age rating4+4+
DeveloperSkytip LLCMETRICS TR DANISMANLIK VE DIS TICARET ANONIM SIRKETI

In-app purchases

6 purchases

Celestial Nav

Subscriptions3
  • PRO Version$1.991 Month
  • PRO Version$7.996 Months
  • PRO Version$9.991 Year
One-time3
  • 7 Day Trial License$0.99
  • 30 Day Trial License$2.99
  • PRO Version Lifetime$24.99
1 purchases

VoyLog

Subscriptions1
  • VoyLog Pro$4.991 Month

Questions

Is Celestial Nav free?
Celestial Nav is free to download, with in-app purchases available.
Is VoyLog free?
VoyLog is free to download, with in-app purchases available.
Do Celestial Nav or VoyLog have ads?
Neither Celestial Nav nor VoyLog shows ads.
Which is updated more often, Celestial Nav or VoyLog?
Celestial Nav ships an update every 3 weeks, and VoyLog every 4 days. Most recently, Celestial Nav was updated on October 1, 2026 and VoyLog on September 26, 2026.

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