Please note that the only in-app purchases available are tips. All functionality is included.

Polar Scope Align will calculate the position of Polaris or σ Octantis in your Polar Scope reticle for your location (using your phone's GPS or entering a location), allowing a quick and accurate polar alignment. It is one of the few programs that are accurate in lower latitudes by correcting for atmospheric refraction (so expect results to agree only with precise software and not most simplistic "polar align" apps - see the "Accuracy" section in the website for details). It will even allow you to measure and correct a centering error of the reticle - very useful for polar scopes that are not easy to adjust (e.g. iOptron ZEQ25). In the settings you can also select from a collection of reticles, one that matches your own - currently iOptron, Astro-Physics, Takahashi, Orion, Skywatcher, Celestron, Meade, Vixen, Bresser, Explore Scientific, Astrotrac, Losmandy, Kenko, Avalon Instruments, Konus, Tuthill, TeleVue Systems (Carton), Telrad reticles are available. Feel free to contact the developer with any questions, feature requests, extra reticle requests and any problems you have with the app. If you like Polar Scope Align, please consider leaving a review on the app store.

Feature list:

-Accurate calculation of Polaris or Sigma Oct for any date and location, including effect of atmospheric refraction (and annual aberration, nutation).
-Use device time/date and GPS location, or manually enter your own.
-Location manager with favorite locations, list of recent locations, online search and offline world database (cities/towns of at least 1000 population).
-Supports a multitude of polar scopes: iOptron, Astro-Physics RAPAS & PASILL, various versions of Takahashi EM-10/11/200/400/500, NJP, PM-1, P2-Z, the latest Orion / Skywatcher, the Classic Skywatcher / Orion / Celestron / Meade / EXOS2 / Bresser, the Telrad, a couple for Astrotrac / Losmandy / Kenko / Avalon, the Vixen Atlux/SX/SXD/SXP/AXD/GP/GP-DX/Polarie Polar Axis Scopes, a Konus and several Polar Finders: Tuthill, Explore Scientific 8x50, Meade 9x60, Vixen Polaris, Celestron 7x50, Carton Optical. PoleMaster help view for South Hemisphere users.
-Full app in red-color night mode - tools switchable to non night mode view.
-Moon phase & lunar Calendar with solar/lunar rise/set and twilight times.
-Wizard to calculate your reticle centering offset and correct or compensate for it.
-Zoomable reticle view.
-Alt-az alignment error display for mounts that calculate it after star alignment (e.g. iOptron iEQ45, CEM60).
-Polar alignment when your scope is not in zero position (for mounts like iOptron ZEQ/CEM on which you can always access the polar scope).
-Remember zero position on Celestron / Skywatcher / Orion etc reticles.
-Approximate daytime / no polarscope polar alignment tool. Great for solar imaging (including eclipses).
-Bubble level (using either gyro or accelerometer) and Compass heading, as well as magnetic declination reading.
-GPS accuracy & elevation data.
-Red/White/LED light.
-Dimming slider.
-Deep Space Object Database with 13000+ objects from several catalogs (Messier, Caldwell, NGC, IC, Herschell 400, Sharpless 2). The database is searchable and fully configurable with filters, various sorting methods etc.
-Over 25 calculators useful for observing and astrophotography, from eyepiece magnification and field of view, to imaging resolution and reducers.
-Xasteria: World astro-weather report based on 7Timer! data.
-Access to the latest water vapor satellite images.
-List of visible ISS passes and Iridium flares.
-iOptron, NexStar and Meade LX200 Star Lists.
-Support for iPhone & iPad from iOS 7 (and iPod Touch, except compass functions).

From version 3.5, an upgrade will anonymously share the iOS version, reticle and tools used (just once), so that I can focus development appropriately.

What’s New

Version 4.9

Why not help out by rating or reviewing the new version. There are never popups inside the app to ask you (annoying!), which results to less reviews than other apps. Here's what's new:
-Updated Meteoblue to point to their new website (their website now requires iOS 9+)
-Tweaks in polar scope instructions

Ratings and Reviews

4.9 out of 5
93 Ratings

93 Ratings

BigTenDad ,

Not Sure about Usefulness

I recently purchased the Pro version of this app. I use it with and Explore Scientific iEXOS-100 eq mount and a William Optics Z61 scope. I have an extremely limited view of the northern sky (none at all — trees and other obstructions). Therefore I need a way to polar align with no view of Polaris. I tried over and over again to “align” my mount. However, I use the compass to get a rough setting for North. Place my iPhone on the mount head and, as I do so, it drifts toward the West. When it finally settles, it wants me to make a correction by almost 15-18 degrees. This is way off. I take the iPhone off the mount, open the compass away from the mount and it again shows the correct North. There must be a way to compensate for this aberration. If there isn’t, the app is worthless for my use. By the way, I do love all the positive responses but, for me, it has not be useful so far.

Update: (3/7/19) Update: I’ve made some adjustments, including purchasing a five inch dovetail and an inexpensive smart phone mount. This gets my iPhone away from the core of the mount. I tried a few nights ago (3/3/19) and was able to do a decent polar alignment using just PS Align Pro. Now I am able to give the app five stars.

Developer Response ,

Hello, and sorry for the trouble you had. However, the review is rather unfair, as the in-app help is very clear about this: you can't just put the phone on the mount, the compass will be way off! That's how magnetometers work. There is an entire section about how to avoid this with various suggestions if you click the info button and read the help for the Daytime Alignment tool. In fact, there have been astronomy publications showing phones on mounts as a good idea and I point out how bad advice that is. I didn't think this would be missed, the header text points you to the info button to learn how to use the tool, perhaps I'll find a way to make it even more clear on the next version.

In any case, because you seem to have a nice setup for astrophotography, I should warn that the Daytime Alignment tool in any case is just a small utility that is meant mainly for aligning for solar tracking or at most visual observation in the night time. If you are planing to try some astrophotography, without access to the north I think you'd have to do the (more cumbersome unfortunately) process of drift alignment.

You can always use the contact form on the Polar Scope Align site to write to me directly with any concerns.

Annoyed consumer 6613 ,

Surprisingly Useful

I purchased the Pro version to give it a try and help me setup an Orion Atlas Pro mount. The app was surprisingly easy to use with great functionality. It can be as easy as opening it up to see what position to align your mount or dive into more detail about various objects in the sky and where they’re located. You can change the mount type being setup for a variety of brands that any backyard astronomer would be familiar with. Additionally, there’s an exceedingly huge catalog of information under the menu. Press the cog wheel and you open up the object list which was a delightful addition that justified supporting the app and purchasing the Pro version.


New to Tracking—Very Helpful!

I recently bought my first tracking mount, iOptron SkyGuider Pro, and found it much easier to find polar alignment with this app.

Same for solar alignment—a little difficult to find a way to mount the phone (which is not the app’s fault), but kept the sun in my camera’s viewfinder at 500mm for more than an hour. Probably could be better if I worked harder on it, but I was able to get an ISS transit. I wish I bought this before the 2017 eclipse!


Dimitrios Kechagias
32 MB

Requires iOS 7.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© 2015 D Kechagias
In-App Purchases
  1. Tip 4x $3.99
  2. Tip 1x $0.99
  3. Tip 10x $9.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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