Comparison

Polar Scope Align Pro vs DuoCorder+

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 Pro

This app assists astronomers with precise polar alignment for telescopes, offering tools for various reticles and low-latitude accuracy. It also includes a comprehensive suite of astro tools, from object databases to calculators and weather reports.

Highlights
  • Accurate polar alignment calculation
  • Support for numerous polar scope reticles
  • Daytime/no polarscope alignment tool
  • Deep Space Object database
  • Astrophotography calculators
  • World astro-weather report
Features
Read full description

Polar Scope Align Pro is a complete toolkit for amateur astronomers: accurate polar alignment, deep-sky observing, astro weather, push-to/manual GoTo, iOptron mount WiFi control, widgets and more. All features and updates are free forever. Optional in-app purchases are just tips to support development. POLAR ALIGNMENT • Calculates Polaris or σ Octantis position for 30+ reticle types: iOptron, Astro-Physics, Takahashi, Skywatcher, Vixen, Celestron, Orion, Astrotrac and others* • Atmospheric refraction correction for accuracy at any latitude • Works with or without a polar scope ALIGNMENT WITHOUT A POLAR SCOPE • Daytime / No Polar Scope Alignment: works day and night with just your phone's gyro • Camera Azimuth Calibration: use sun/moon/stars to calibrate gyro and align accurately without a compass, immune to magnetic interference • Laser / Hop Align: nighttime alignment for maximum accuracy with a laser or a scope with no view of Polaris • Live sky map guides you to the celestial pole in real time • Sun Finder helps you point your filtered telescope/telephoto to the Sun PUSH TO (MANUAL GOTO) • Attach your phone to any scope and convert it to manual/push GoTo • Select from a large database and use direct push or more accurate hop-to mode DEEP SKY OBJECT DATABASE • 22,000+ objects with altitude graphs, rise/set times and more info • Save and manage curated observing lists • Filter, search, sort and push to any target XASTERIA ASTRO WEATHER • Hourly astronomy forecasts from 7Timer, OpenWeather, MET Norway and Apple Weather, plus a configurable Multi-source forecast • Animated satellite Cloud Map with recent EUMETSAT and NASA infrared imagery • Aurora forecasts • ISS and bright satellite passes with an All Sky night chart, individual sky charts, live map tracking, and Tiangong and Hubble views • Solar eclipse tool with past and future eclipses, live mode with audio cues • Experimental eclipse camera for automated photoshoots of partial phase, diamond ring, Baily's beads, totality bracketing • Interactive light pollution map using World Atlas and recent VIIRS data CALCULATORS & TOOLS • 30+ calculators for observing and astrophotography • Moon phase calendar with altitude graphs • Solar eclipse calculator and simulator • Bubble level & Compass IOPTRON WIFI MOUNT CONTROL • Connect to WiFi-enabled iOptron mounts (HAE, HAZ, HEM, CEM, GEM and more) • Automatic date/time/location setup • Switch between Equatorial and Alt-Az on mounts that support both • Move & Sync: directional control with a live sky map • Point GoTo: aim your phone at a patch of sky and send the mount there • Current Point Query: find out what the mount is pointing at • GoTo any object from the DSO Database NIGHT-FRIENDLY • Red, green or white night mode with dimmer WIDGETS • Configurable Tonight and Multi astronomy weather forecasts • Upcoming bright satellite passes • Aurora probability, activity forecast and NOAA aurora map * Full list of supported reticles: Astro-Physics RAPAS & PASILL, iOptron, the latest Orion / Skywatcher, the Classic Skywatcher / Orion / Celestron / Meade / EXOS2 / Bresser / MSM, various versions of Takahashi EM-10/11/200/400/500, NJP, PM-1, P2-Z, the Telrad, Rigel QuikFinder, a couple for Astrotrac / Losmandy / Kenko / Avalon, the Vixen PF-L/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.

About

DuoCorder+

Transform your iPhone into a handheld sensor scanner. Explore environmental data like sound, air pressure, and magnetic fields with a retro-futuristic interface. Set custom alerts and track 24-hour trends for your sensor readings.

Highlights
  • Live sensor scanning
  • Retro-futuristic display
  • Customizable alerts
  • 24-hour trend charts
  • Metal detector mode
  • Data export (CSV)
  • Privacy-focused design
Features
Currently charting
Read full description

DuoCorder turns your iPhone into a handheld sensor scanner. See what your phone can sense about the world around you, live, on one retro-futuristic display. ONE-TAP FULL SCAN Press SCAN and DuoCorder samples every sensor for ten seconds, then explains what it found in plain language: "No magnetic anomalies", "Air pressure falling", "Conversation-level sound". Save the report or share it. MORE THAN A DOZEN LIVE INSTRUMENTS • Motion: acceleration, rotation, tilt and a bubble level • Compass: true and magnetic heading, 3-axis magnetic field strength • Air pressure: barometer, sea-level pressure, altitude change, pressure trend (iPhones with a barometer) • Light: ambient light level estimated from the camera's exposure • Sound: level in decibels, a live spectrum, and a scrolling spectrogram • Pitch: names the strongest note you hear, with how sharp or flat it is • Position: coordinates, speed, course, accuracy and the nearest place name • Activity: steps, distance, floors climbed, cadence and pace • Bluetooth radar: nearby devices, signal strength and a rough range estimate • Your phone: battery, CPU, memory, storage, temperature and network METAL DETECTOR MODE Sweep the phone slowly and listen. The tone rises in pitch and the haptic ticks speed up as the magnetic field changes near metal. YOUR OWN ALERTS Create rules such as "pressure falling faster than 2 hPa/hour", "magnetic field above 70 µT" or "battery below 20%". DuoCorder chirps, buzzes and flashes the screen when one triggers, and keeps a history of recent alerts. Alerts work while the app is open. 24-HOUR TRENDS DuoCorder records your readings while it is open and keeps the last 24 hours. Chart any sensor over 5 minutes to a full day, drag to inspect values, and see your alert thresholds on the chart. SNAPSHOTS AND SHARING Save a snapshot of any page, with your location, then browse your log or export everything as a CSV file. Share a full readable report in one tap. EASY TO LEARN Tap any reading to see what it means, view its trend or set an alert. A quick guide explains the controls, and every button is clearly labelled. BUILT FOR BIG AND FOLDABLE SCREENS The layout fills iPhone, iPad and wide two-panel displays, with the display on top and the keys below. PRIVATE BY DESIGN Everything stays on your device. There are no accounts, no ads, no analytics and no tracking. The microphone, camera and Bluetooth run only while the page or scan that needs them is open. Sound is analysed live and never recorded. The camera is used only for its light reading, and no photos or video are saved. GOOD TO KNOW Readings come from your phone's built-in sensors and are approximate. Which sensors you see depends on your device; for example, the barometer is not in every iPhone. DuoCorder is for curiosity and learning, not for medical, safety, navigation or professional use.

Screenshots

Polar Scope Align Pro4 screens
DuoCorder+4 screens

Verdict

The call

The clearest difference is ratings volume: Polar Scope Align Pro at 310 against DuoCorder+'s 1. Polar Scope Align Pro also leads on iOS requirement (13.0 vs 17.0). DuoCorder+'s advantage is chart position (#56 vs unranked) and price ($2.99 vs $4.99). On rating, 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

Polar Scope Align Pro costs $4.99 and DuoCorder+ $2.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.9 for Polar Scope Align Pro against 5.0 for DuoCorder+. That said, the two scores are not equally well evidenced: Polar Scope Align Pro has 310 ratings behind it against 1, so its average is the more settled of the two.

Scorecard5 real differences · 6 level
Polar Scope Align Pro versus DuoCorder+: the parameters behind the verdict, then further details
ParameterPolar Scope Align ProDuoCorder+
Price$4.99$2.99 — better
Rating4.9 (310 ratings)5.0 (1 ratings) — better
Positive reviews96.7% of reviews—
Number of ratings310 — better1
Update frequencyEvery 2 months—
AdsNoNo
In-app purchasesNoNo
MonetizationFree with in-app purchases — betterPaid
Best chart rank—#56 — better
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS13.0 — better17.0
Further details — not scored
Size33 MB1 MB
Age rating4+4+
DeveloperDimitrios KechagiasJames Roche

Customer experience

Polar Scope Align Pro

All ratings309 ratings
Positive99.0%
Neutral0.0%
Negative1.0%
Written reviews272 reviews
Positive96.7%
Neutral0.7%
Negative2.6%

DuoCorder+

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%

Bugs and requests

Polar Scope Align Pro

Reported bugs

2 issues
  • Weather Updates Not Working
  • Compass Deflected by Mount

Requested features

2 requests
  • Add Observation Recording Feature
  • Add Push To Option for DSO Objects

DuoCorder+

Not enough reviews yet to summarise bugs or requests.

In-app purchases

None

Polar Scope Align Pro

No in-app purchases

None

DuoCorder+

No in-app purchases

Questions

Is Polar Scope Align Pro free?
Polar Scope Align Pro costs $4.99, with no in-app purchases.
Is DuoCorder+ free?
DuoCorder+ costs $2.99, with no in-app purchases.
Which has better reviews, Polar Scope Align Pro or DuoCorder+?
DuoCorder+ is rated higher. Polar Scope Align Pro averages 4.9 out of 5 from 310 ratings, while DuoCorder+ averages 5.0 from 1 ratings.
Do Polar Scope Align Pro or DuoCorder+ have ads?
Neither Polar Scope Align Pro nor DuoCorder+ shows ads.

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