Comparison

Moon phases assist vs Flat Earth Pro

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

Head to head
About

Moon phases assist

Visually learn about moon phases and celestial body positions. Interactive diagrams help answer questions about why the moon changes appearance and how the sun's height varies with seasons. Understand the solar system through intuitive overhead and celestial sphere views.

Highlights
  • Visual moon phase learning
  • Celestial body position diagrams
  • Interactive dial for position checking
  • Answers to astronomy questions
  • Overhead and celestial sphere views
  • Improved features through overhaul
Features
Read full description

This app allows you to visually learn about the different phases of the moon depending on the positions of the moon, the Earth, and the Sun. The app has undergone a major overhaul to improve its features! Why does the moon have different phases? Why does the height of the Sun change depending on the season? These diagrams provide easy answers to these questions! You can intuitively grasp the positions of the Sun, the Earth, and the moon through overhead and celestial sphere diagrams! What are the positions of the Sun and the moon during a full moon? Where is the Sun when the waning crescent transits the meridian? You can answer these questions by turning the dial and checking their positions! ※The size and distance of celestial objects are not drawn to scale but exaggerated for easier understanding. ※For easier understanding, the Earth's orbit is made circular instead of elliptic while the inclination of the moon's orbit has been omitted.

About

Flat Earth Pro

Visualize celestial body positions, daylight coverage, and moon phases on an Earth projection. Explore sun and moon overhead positions, rise/set times, and lunar details. Features offline functionality and a local weather forecast.

Highlights
  • Daylight coverage visualization
  • Sun and moon overhead positions
  • Rise and set times
  • Moon phases and libration
  • Offline functionality
  • Local weather forecast
Features
Currently charting
Read full description

Flat Earth app is a tool used to visualise daylight coverage, sun and moon overhead positions, rise and set times, moon phases, lunar parallactic angle and liberations, and much more in a simple and easy to read Azimuthal projection of the earth. Once you start the application, you will be informed immediately about the current zenith (overhead) position of the sun and moon, the current phase and parallactic angle of the moon, day and night map and much more relative to any observer position on earth. With one touch you can rotate clockwise or counter-clockwise to move time to the future or to the past and visualise the orbital motion of Sun, Moon, and 5 more optional celestial bodies realtime and with great accuracy. All of the core features of the app work offline including time zones. The graphical positions of the celestial bodies on the map represent the zenith (overhead) position relative to the app time. The direction of the celestial body (azimuth) in your local sky and its altitude can be visualised as well as the sky dome relative to any location through the navigation tab. The Flat Earth Application includes: - Lunar Perigee and Apogee in realtime as well as event schedule. - Lunar Phases in realtime as well as event schedule. - Local and regular Compass, and directions for the current sky position for all of the available celestial bodies. - Altitude , azimuth and current zenith position are featured and easily accessible for every feature celestial body. - Day light coverage visualisation over the earth for any particular time instant. - The rise and set times for any location on earth for all the of the available celestial bodies. - All time zones. - Moon libration and Orientation at any date and time and at any location. - Unique local weather forecast integrated within the app in app time controller. - Unlimited Moon, Sun and Earth Data at ANY date and time. - The ability to take and share a high resolution shot of the earth a moon. - Custom Notification at any date and time.

Screenshots

Moon phases assist4 screens
Flat Earth Pro4 screens

Verdict

The call

The clearest difference is price: Moon phases assist at Free against Flat Earth Pro's $3.99. Flat Earth Pro's advantage is rating (4.9 vs 3.5) and ads (none vs shown). On update cadence, in-app purchases, device support and iOS requirement 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

Moon phases assist is free to download; Flat Earth Pro costs $3.99 up front. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

Flat Earth Pro holds the better App Store score, 4.9 against 3.5. That said, the two scores are not equally well evidenced: Flat Earth Pro has 122 ratings behind it against 2, so its average is the more settled of the two. Written reviews point the same way: 67% of Moon phases assist's written reviews are positive against 81% of Flat Earth Pro's.

UpkeepUpdate frequency

Moon phases assist ships an update every 3 weeks, Flat Earth Pro every 6 weeks. The most recent releases landed on November 2, 2026 and November 7, 2026 respectively.

Scorecard7 real differences · 4 level
Moon phases assist versus Flat Earth Pro: the parameters behind the verdict, then further details
ParameterMoon phases assistFlat Earth Pro
PriceFree — better$3.99
Rating3.5 (2 ratings)4.9 (122 ratings) — better
Positive reviews66.7% of reviews81.3% of reviews — better
Number of ratings2122 — better
Update frequencyEvery 3 weeks — betterEvery 6 weeks
AdsYesNo — better
In-app purchasesNoNo
MonetizationAd-supportedFree — better
Best chart rank—#182 — better
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS13.013.0
Further details — not scored
Size64 MB224 MB
Age rating4+4+
DeveloperPlus Inc. (Japan)Othman Alzahrani

Customer experience

Moon phases assist

All ratings2 ratings
Positive50.0%
Neutral50.0%
Negative0.0%
Written reviews9 reviews
Positive66.7%
Neutral22.2%
Negative11.1%

Flat Earth Pro

All ratings108 ratings
Positive97.2%
Neutral0.0%
Negative2.8%
Written reviews32 reviews
Positive81.3%
Neutral0.0%
Negative18.8%

In-app purchases

None

Moon phases assist

No in-app purchases

None

Flat Earth Pro

No in-app purchases

Questions

Is Moon phases assist free?
Moon phases assist is free to download, with no in-app purchases.
Is Flat Earth Pro free?
Flat Earth Pro costs $3.99, with no in-app purchases.
Which has better reviews, Moon phases assist or Flat Earth Pro?
Flat Earth Pro is rated higher. Moon phases assist averages 3.5 out of 5 from 2 ratings, while Flat Earth Pro averages 4.9 from 122 ratings.
Do Moon phases assist or Flat Earth Pro have ads?
Moon phases assist shows ads; Flat Earth Pro does not.
Which is updated more often, Moon phases assist or Flat Earth Pro?
Moon phases assist ships an update every 3 weeks, and Flat Earth Pro every 6 weeks. Most recently, Moon phases assist was updated on November 2, 2026 and Flat Earth Pro on November 7, 2026.

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