Comparison

Polar Scope Align vs Local Sidereal Time

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

Local Sidereal Time

This app calculates local sidereal time, a system astronomers use to locate celestial objects. It can also be used for personal development, with studies suggesting increased psychic abilities during specific sidereal times. The pro version offers advanced features like notifications and map-based calculations.

Highlights
  • Calculate local sidereal time
  • Astronomy celestial object location
  • Potential psychic ability enhancement
  • Pro version notifications
  • Pro version map-based calculation
  • Pro version date/time conversion
Features
Read full description

Sidereal helps you track local sidereal time from your current location or any place you want to check. It is designed for people interested in the 13:30 LST window discussed in remote-viewing literature, while also supporting any custom sidereal target you want to follow. Use Sidereal to: View a live local sidereal clock based on your current location Calculate local sidereal time manually from longitude, date, and time Search for a city or address and see the result with map support Generate the next 31 upcoming hits for your selected sidereal target Schedule the next 30 days of on-device alerts Export future times to CSV and export events to your calendar Customize your target LST, alert timing, full-window notifications, night viewing, and map visibility Sidereal starts with 13:30 LST as the default target, but you can change it in Settings to track any local sidereal time. The app includes a trial, with Pro unlocking continued access to advanced tools and planning features.

Screenshots

Polar Scope Align4 screens
Local Sidereal Time4 screens

Verdict

The call

The clearest difference is ads: Local Sidereal Time at none against Polar Scope Align's shown. Local Sidereal Time also leads on ratings volume (1.1K vs 173). Polar Scope Align's advantage is review sentiment (91% vs 71%) and iOS requirement (13.0 vs 15.0). On price, rating, update cadence and in-app purchases 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 and Local Sidereal Time sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

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 Local Sidereal Time. That said, the two scores are not equally well evidenced: Local Sidereal Time has 1.1K ratings behind it against 173, 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 71% of Local Sidereal Time's.

UpkeepUpdate frequency

Polar Scope Align ships an update every 2 months, Local Sidereal Time every 4 months. The most recent releases landed on October 21, 2026 and October 17, 2026 respectively.

Scorecard4 real differences · 6 level
Polar Scope Align versus Local Sidereal Time: the parameters behind the verdict, then further details
ParameterPolar Scope AlignLocal Sidereal Time
PriceFreeFree
Rating4.7 (173 ratings)4.7 (1.1K ratings) — better
Positive reviews91.3% of reviews — better70.7% of reviews
Number of ratings1731.1K — better
Update frequencyEvery 2 months — betterEvery 4 months
AdsYesNo — better
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.0 — better15.0
Further details — not scored
Size23 MB20 MB
Age rating4+4+
DeveloperDimitrios KechagiasScott Spiller

Customer experience

Polar Scope Align

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

Local Sidereal Time

All ratings1,032 ratings
Positive92.8%
Neutral3.6%
Negative3.6%
Written reviews41 reviews
Positive70.7%
Neutral4.9%
Negative24.4%

User reviews

Polar Scope Align

From 173 App Store ratings

What we love

  • 🎯 Extensive reticle options for various telescope mounts
  • 👍 User-friendly and intuitive interface
  • 🆓 Powerful free version with no popup ads
  • 🔴 Red night vision mode preserves dark adaptation
  • 📍 Accurate GPS-based location detection

Room to improve

  • 🐛 Inconsistent accuracy with metal mounts/tripods
  • 📱 Font size too small for comfortable reading
  • 🎯 Center dot in reticle obscures precise alignment
  • 📍 Limited effectiveness for southern hemisphere (Sigma Octantis is dim)
  • ❓ Steep learning curve for beginners without proper guidance

Local Sidereal Time

From 1.1K App Store ratings

What we love

  • 👍 Easy to use
  • 🚀 Useful app
  • 💡 Helpful notifications
  • 👍 Great customer service
  • 💡 Excellent tool

Room to improve

  • 🐛 Alarm doesn't work
  • 🐛 Crashes frequently
  • 🔒 Pro purchase issues
  • 🐛 Notification issues

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

Local Sidereal Time

Reported bugs

4 issues
  • Alarm doesn't work
  • Crashes when loading
  • Notification issues
  • Pro purchase restoration not working

Requested features

4 requests
  • Add alarm feature
  • Allow setting location manually
  • Improve notification handling
  • Automatically adjust for daylight saving time

In-app purchases

3 purchases

Polar Scope Align

One-time3
  • Tip 1x$0.99
  • Tip 4x$3.99
  • Tip 10x$9.99
1 purchases

Local Sidereal Time

One-time1
  • Pro$4.99

Questions

Is Polar Scope Align free?
Polar Scope Align is free to download, with in-app purchases available.
Is Local Sidereal Time free?
Local Sidereal Time is free to download, with in-app purchases available.
Which has better reviews, Polar Scope Align or Local Sidereal Time?
Local Sidereal Time is rated higher. Polar Scope Align averages 4.7 out of 5 from 173 ratings, while Local Sidereal Time averages 4.7 from 1.1K ratings.
Do Polar Scope Align or Local Sidereal Time have ads?
Polar Scope Align shows ads; Local Sidereal Time does not.
Which is updated more often, Polar Scope Align or Local Sidereal Time?
Polar Scope Align ships an update every 2 months, and Local Sidereal Time every 4 months. Most recently, Polar Scope Align was updated on October 21, 2026 and Local Sidereal Time on October 17, 2026.

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