ioda vs Polar Scope Align
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
ioda
This scientific application allows users to read and visualize data from various file formats commonly used in astronomy and high-energy physics. It supports formats like FITS, ROOT, HDF5, JPG, and FOG, and can execute specific script files.
- Read FITS, ROOT, HDF5, JPG, and FOG files
- Browse and visualize data
- Execute .kumac files
- Includes gopaw core
- Supports various scientific data schemas
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ioda should be read "IO-DA", for Input/Output and for Data Analysis. It is a scientific application that permits to read files at various formats as FITS used in astronomy, ROOT and AIDA used in high energy physics (HEP), HDF5 with the g4tools data schema semantic, JPG format to store images and FOG developed at CEA/Saclay (France) to describe the LHC/ATLAS geometry. ioda permits to browse these files and visualise some of their data. Since 1.14.x, ioda contains the gopaw (=Good Old PAW) core and can execute .kumac files.
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.
- 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
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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.
Screenshots
Verdict
The clearest difference is review sentiment: Polar Scope Align at 91% against ioda's 33%. Polar Scope Align also leads on rating (4.7 vs 3.0) and ratings volume (171 vs 2). ioda's advantage is in-app purchases (none vs 3) and ads (none vs shown). On price 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
Both are free to download. Polar Scope Align sells 3 one-off in-app purchases. ioda asks for nothing beyond the download.
Polar Scope Align holds the better App Store score, 4.7 against 3.0. That said, the two scores are not equally well evidenced: Polar Scope Align has 171 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 33% of ioda's written reviews are positive against 91% of Polar Scope Align's.
ioda ships an update every 5 months, Polar Scope Align every 2 months. The most recent releases landed on September 27, 2026 and October 14, 2026 respectively.
| Parameter | ioda | Polar Scope Align |
|---|---|---|
| Price | Free | Free |
| Rating | 3.0 (2 ratings) | 4.7 (171 ratings) — better |
| Positive reviews | 33.3% of reviews | 91.3% of reviews — better |
| Number of ratings | 2 | 171 — better |
| Update frequency | Every 5 months | Every 2 months — better |
| Ads | No — better | Yes |
| In-app purchases | No — better | Yes |
| Monetization | Free — better | Free with in-app purchases |
| Devices | iPhone, iPad, iPod | iPhone, iPad, iPod |
| Requires iOS | 8.0 — better | 13.0 |
| Further details — not scored | ||
| Size | 64 MB | 23 MB |
| Age rating | 4+ | 4+ |
| Developer | Guy Barrand | Dimitrios Kechagias |
Customer experience
ioda
Polar Scope Align
Bugs and requests
ioda
Not enough reviews yet to summarise bugs or 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
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- 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
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- Better beginner onboarding and instructions
- More robust alternative alignment methods for southern hemisphere
In-app purchases
ioda
No in-app purchases
Polar Scope Align
- Tip 1x$0.99
- Tip 4x$3.99
- Tip 10x$9.99









