Comparison

QiMenChart vs Polygon

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

Head to head
About

QiMenChart

This app generates historical charts for years, months, days, and hours using traditional Chinese calendrical methods. It allows users to orient the chart with a compass based on their position. The application focuses solely on chart plotting without providing any analysis or user settings.

Highlights
  • Plot Year, Month, Day, Hour Charts
  • Chai Bu and Zhi Run Methods
  • Year Range 1800-9999
  • Compass Orientation
  • Chart Plotting Only
Read full description

* Plot Year Chart, Month Chart, Day Chart, Hour Chart (拆补法 Chai Bu Method) and (置闰法 Zhi Run Method) * Year range from 1800 to 9999 * Turn on the compass and rotate the chart to your facing or sitting * Just plot the chart, no analysis and other functions available. * No user settings.

About

Polygon

Calculate complex properties of any polygonal figure, including centroids, moments of inertia, and perimeter. Simply input vertex coordinates for instant results, saving significant time on tedious calculations.

Highlights
  • Polygon Centroids
  • Moments of Inertia (Ix, Iy, Ixy)
  • Polar Moment of Inertia
  • Radius of Gyration
  • Principal Moments of Inertia
  • Area and Perimeter
  • Side Lengths
  • Hollow Sections
Features
Read full description

Polygon will allow you to calculate complex and tedious calculations related to any polygonal figure, whether concave or convex, regular or irregular, in a simple and instantaneous way: - Polygon Centroids - Moments of Inertia Ix, Iy, Ixy - Polar Moment of Inertia - Radius of gyration - Principal Moments of Inertia (Iu, Iv and their respective angles) - Area and Perimeter of the polygon - Length of each side of the polygon - Even incorporate hollow sections - Rotate the axes to a custom angle - Define new custom axes at any point - and much more You just have to enter the coordinates of the vertices of your polygon and press the button and it will immediately calculate all the previous properties, saving valuable time. Subscription Terms: Payment will be charged to Itunes Account at confirmation of purchase. Subscription automatically renews unless auto-renew is turnerd off at least 24-hours before the end of the current period. Account will be charged for renewal within 24-hour prior to the end of the current period, and identify the cost of the renewal. Subscriptions may be managed by the user and auto-renewal may be turned off by going to the user's Account Setting after purchase. No cancellation of the current subscription is allowed during active subscription period. For in-app purchases and subscriptions, see Terms of Use: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

QiMenChart4 screens
Polygon4 screens

Verdict

The call

The clearest difference is price: Polygon at Free against QiMenChart's $6.99. Polygon also leads on update cadence (weekly vs every 6 months). QiMenChart's advantage is in-app purchases (none vs 4) and iOS requirement (15.6 vs 17.0). On ads 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

Polygon is free to download; QiMenChart costs $6.99 up front. Polygon sells 4 in-app purchases, starting at $2.99 per month. QiMenChart asks for nothing beyond the download.

UpkeepUpdate frequency

QiMenChart ships an update every 6 months, Polygon weekly. The most recent releases landed on September 21, 2026 and September 20, 2026 respectively.

Scorecard5 real differences · 5 level
QiMenChart versus Polygon: the parameters behind the verdict, then further details
ParameterQiMenChartPolygon
Price$6.99Free — better
Rating—3.0 (1 ratings) — better
Positive reviews0.0% of reviews—
Number of ratings—1 — better
Update frequencyEvery 6 monthsWeekly — better
AdsNoNo
In-app purchasesNo — betterYes
MonetizationPaidFreemium — better
DevicesiPhone, iPad, iPod — betteriPhone, iPad
Requires iOS15.6 — better17.0
Further details — not scored
Size6 MB29 MB
Age rating4+4+
DeveloperLAY KHIM TANAdrian Caballero

Customer experience

QiMenChart

Written reviews1 reviews
Positive0.0%
Neutral0.0%
Negative100.0%

Polygon

All ratings1 ratings
Positive0.0%
Neutral100.0%
Negative0.0%

In-app purchases

None

QiMenChart

No in-app purchases

4 purchases

Polygon

Subscriptions3
  • Pro Access$2.991 Month
  • Pro Access$4.996 Months
  • Pro Access$6.991 Year
One-time1
  • Pro Access$9.99

Questions

Is QiMenChart free?
QiMenChart costs $6.99, with no in-app purchases.
Is Polygon free?
Polygon is free to download, with in-app purchases available.
Do QiMenChart or Polygon have ads?
Neither QiMenChart nor Polygon shows ads.
Which is updated more often, QiMenChart or Polygon?
QiMenChart ships an update every 6 months, and Polygon weekly. Most recently, QiMenChart was updated on September 21, 2026 and Polygon on September 20, 2026.

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