Comparison

Polar Scope Align vs NAPA

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

Head to head
About

Polar Scope Align

This app calculates the precise position of celestial poles in your telescope's polar scope reticle for accurate alignment. It supports a wide range of reticles and corrects for atmospheric refraction, offering precision even at lower latitudes. Features include night mode, moon phase, and astronomical databases.

Highlights
  • Polaris/Sigma Octantis position calculation
  • Atmospheric refraction correction
  • Reticle centering error correction
  • Supports numerous reticle types
  • Red-color night mode
  • Moon phase and astronomical databases
Features
Read full description

Polar Scope Align is a free, ad-supported polar alignment app for iPhone and iPad. It calculates the position of Polaris or σ Octantis in your polar scope reticle for your location, date and time, helping you get a quick and accurate polar alignment with an equatorial mount. POLAR SCOPE ALIGNMENT • Accurate Polaris and Sigma Octantis position for your date and location • Atmospheric refraction correction for better accuracy, especially at lower latitudes - readings may differ slightly from simpler apps that skip this correction, but will agree with precise sources (USNO, scientific software) • Automatic time and location • Manual location support • Reticle centering-error measurement and correction • Zero-position help for common Celestron / Sky-Watcher / Orion style reticles • Full red night-mode interface SUPPORTED RETICLES Polar Scope Align supports 35+ polar scope and finder reticle types, including: iOptron, Astro-Physics RAPAS & PASILL, Takahashi (EM-10/11/200/400/500, NJP, PM-1, P2-Z), Sky-Watcher / Orion (including EQ6/AZ-EQ and Star Adventurer), Celestron, Meade, EXOS2, Bresser, Vixen (Atlux/SX/SXD/SXP/AXD/GP/GP-DX, Polarie), Astrotrac, Losmandy, Kenko, Avalon, Konus, Telrad, Rigel QuikFinder, and several older polar finders (Tuthill, Explore Scientific, Meade 9x60, Vixen Polaris, Celestron 7x50, Carton Optical). OBSERVING TOOLS The free version also includes: • Moon phase • Messier, Caldwell and bright-star database • DSS image downloads for included database objects • Saved, editable and printable DSO lists • 8 astronomy calculators for observing and imaging • Sample Pro tools available from Settings, including aurora forecast • iOptron WiFi Connect - report mount status, set mount Time/Date/Location LOOKING FOR ALIGNMENT WITHOUT A POLAR SCOPE? Polar Scope Align Pro adds the advanced tools many users search for: • Daytime / No Polar Scope Alignment • Camera Azimuth Calibration using the Sun, Moon, planets or bright stars • Laser / Hop Align for night alignment when Polaris is blocked • Push To / manual GoTo for non-GoTo telescopes • Live sky maps for Daytime Alignment, Laser / Hop Align, Push To and Hop To • Full 22,000+ object DSO database • Xasteria astro weather, aurora, satellite passes and widgets • 30+ calculators • Bubble level, compass and iOptron WiFi mount control • Apple Watch companion app • No ads If you only need accurate polar-scope alignment, this free version is a capable tool. If you want alignment without a polar scope, observing planning, weather and field tools, Pro is the complete version.

About

NAPA

Explore the night sky with this astronomy and planetarium app. Identify stars, constellations, and planets by pointing your device at the sky. Plan future observations by adjusting the time and date.

Highlights
  • Point and observe celestial objects
  • Star map functionality
  • Time adjustment for observation planning
  • Simulate planet positions
  • Locate specific celestial objects
  • Real images of deep sky objects
Features
Read full description

NAPA - Star Map NARIT Astronomy & Planetarium Application, or “NAPA” is an astronomy and planetarium app that will help guide you to the night sky. Identify those dots in the sky. Learn about stars, constellations, planets, and other deep sky objects by simply pointing your phone at the sky. Adjust the time and NAPA can be used as a star map to help plan your future observation. Familiarize yourself and learn more about the patterns that make up the night sky. Select and use NAPA to locate deep sky objects that you can locate with a binocular or small telescope. NAPA is made by professional and amateur astronomers, along with public outreach professionals with the aim to help bridge the gap, making astronomy accessible to everyone. This app is made free to use with the aim to assist schoolteachers and public outreach personnels with their engagement with the public. Unlock the pro version (coming soon) to access the full potential of this app. Turn your phone into powerful tools that can help you with your observation and stargazing events with features that will assist in your astronomical needs. NAPA features: • Point and observe: Display the celestial objects in the position of the sky that your smart device is pointing at. • Point and drag the screen to turn this app into a star map. • Adjust the time to plan your observations at any given date and time. • Simulate the positions of planets that you can see at any time. • Select constellations, planets, or deep sky objects of interest and locate its position in the sky. • Real images of deep sky objects

Screenshots

Polar Scope Align4 screens
NAPA4 screens

Verdict

The call

The clearest difference is in-app purchases: NAPA at none against Polar Scope Align's 3. NAPA also leads on ads (none vs shown). Polar Scope Align's advantage is ratings volume (173 vs 3) and review sentiment (91% vs 75%). On price, rating, update cadence 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. Polar Scope Align sells 3 one-off in-app purchases. NAPA asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.7 for Polar Scope Align against 4.7 for NAPA. That said, the two scores are not equally well evidenced: Polar Scope Align has 173 ratings behind it against 3, so its average is the more settled of the two. Written reviews are what separate them: 91% of Polar Scope Align's written reviews are positive against 75% of NAPA's.

UpkeepUpdate frequency

Both ship on a similar rhythm, roughly every 2 months. The most recent releases landed on October 21, 2026 and October 9, 2026 respectively.

Scorecard5 real differences · 5 level
Polar Scope Align versus NAPA: the parameters behind the verdict, then further details
ParameterPolar Scope AlignNAPA
PriceFreeFree
Rating4.7 (173 ratings) — better4.7 (3 ratings)
Positive reviews91.3% of reviews — better75.0% of reviews
Number of ratings173 — better3
Update frequencyEvery 2 monthsEvery 2 months
AdsYesNo — better
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesFree — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.012.0 — better
Further details — not scored
Size23 MB287 MB
Age rating4+4+
DeveloperDimitrios KechagiasNational Astronomical Research Institute of Thailand (Public Organization)

Customer experience

Polar Scope Align

All ratings171 ratings
Positive92.4%
Neutral0.6%
Negative7.0%
Written reviews173 reviews
Positive91.3%
Neutral1.7%
Negative6.9%

NAPA

All ratings3 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews4 reviews
Positive75.0%
Neutral25.0%
Negative0.0%

Bugs and requests

Polar Scope Align

Reported bugs

6 issues
  • Date and time dial do not match correctly
  • GMT and LST times appear to be switched
  • App crashes or fails to initialize for some users
  • Alignment accuracy varies inconsistently between sessions
  • Location detection issues with cell tower vs GPS
Show 1 more
  • Reticle display not rendering properly in some cases

Requested features

7 requests
  • Online video tutorials demonstrating all features
  • Remove or reduce center dot size in reticle
  • Larger, bolder font options for better readability
  • Brighter star options for southern hemisphere alignment
  • Smaller ad button or ad customization
Show 2 more
  • Better beginner onboarding and instructions
  • More robust alternative alignment methods for southern hemisphere

NAPA

Not enough reviews yet to summarise bugs or requests.

In-app purchases

3 purchases

Polar Scope Align

One-time3
  • Tip 1x$0.99
  • Tip 4x$3.99
  • Tip 10x$9.99
None

NAPA

No in-app purchases

Questions

Is Polar Scope Align free?
Polar Scope Align is free to download, with in-app purchases available.
Is NAPA free?
NAPA is free to download, with no in-app purchases.
Which has better reviews, Polar Scope Align or NAPA?
Polar Scope Align is rated higher. Polar Scope Align averages 4.7 out of 5 from 173 ratings, while NAPA averages 4.7 from 3 ratings.
Do Polar Scope Align or NAPA have ads?
Polar Scope Align shows ads; NAPA does not.
Which is updated more often, Polar Scope Align or NAPA?
Polar Scope Align ships an update every 2 months, and NAPA every 2 months. Most recently, Polar Scope Align was updated on October 21, 2026 and NAPA on October 9, 2026.

Other comparisons