Comparison

Leonhard Euler vs Parallel Chronology

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

Head to head
About

Leonhard Euler

Features
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With this app students learn about the life and contributions to mathematics made by Leonhard Euler. It discusses his major mathematical discovers including his identity theorem which is considered to be one of his most significant accomplishements. Leonhard Euler is considered to be the greatest mathematician of the Eighteenth Century. He was born in Basel Switzerland, where he eventually completed a masters degree from the university there in just three years. Early in his life Leonhard Euler's parents wanted him to join the clergy. But young Leonhard was drawn to mathematics. Fortunately the great mathematician Johann Bernoulli recognized that Euler was a mathematical genius and agreed to tutor him. Health problems plagued Euler for most of his life. He eventually became blind but still continued to produce significant work in mathematics. Using this app students learn about his amazing life. It includes introductory information about mathematics. We hope that this app will inspire students to pursue careers in math. Students will enjoy using this graphically illustrated, interactive learning tool. The timeline feature presents key events in the life of Euler. Tapping on timeline points will bring up descriptions of historically significant events in the history of mathematics and the role that Euler played. A quiz function helps students demonstrate their comprehension of the reading material. Key concepts of both math and science are shown in colorful illustrations. We hope this app will inspire students to study math. The app shows that Leonhard Euler certainly deserves the place he has earned in the history of mathematics.

About

Parallel Chronology

Explore historical events and fictional timelines side-by-side. Compare information across different categories and time periods, from the dawn of the universe to the present and beyond. Discover new insights by juxtaposing diverse data points on an infinitely scrolling timeline.

Highlights
  • Side-by-side information display
  • Story units for comparative analysis
  • Infinite scroll timeline (99.9 billion BC to 99.9 billion AD)
  • Tool for historical discovery
  • Supports custom fictional data
  • Links to Wikipedia for details
  • Universal device support (iPhone/iPad)
Features
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## Parallel comparison ## You can display various informations with time attributes unit of year side by side, regardless of a specific category such as Japanese history or world history. ## Story Unit ## Multiple data are displayed together in a unit "Story", so you can easily compare informations along with different viewpoints. ## Almost infinite scroll ## You can display Informations from before the birth of the universe (13.8 billion years ago) to the present on the same timeline. It is almost infinite scroll by practical usage. It is about a range of 99.9 billion BC to 99.9 billion AD. ## Tool for new discovery ## Comparing historical figures of various countries, or history of natural disasters and wars, which may deepen your understanding of history or make new discoveries. ## It's OK on any data ## You can create Story and datas of it. It's OK not only data on history, but fictional datas such as in novels, movies, and completely original datas. ex. * History of characters in SF novels * Genealogy of ancestors * Data for memorization of historical terms ## Easy to check detail informations ## Each data on the chronology is linked to page of Wikipedia, so if its title exists, you can check the detail information immediately. This is the same even if it is data created by yourself. ## Universal devices ## This app supports universal devices, so you can use comfortably with either iPhone of iPad. In addition, you can rotate either horizontally or vertically. So you can rotate it according to your preference, for example in case you want to display a longer period, want to compare a lot of informations. This app is developed as you can use even if on 4-inch iPhone SE. If you will be using on large resolution device like iPad Pro, more comfortable.

Screenshots

Parallel Chronology3 screens

Verdict

The call

The clearest difference is price: Parallel Chronology at Free against Leonhard Euler's $1.99. Parallel Chronology also leads on iOS requirement (13.0 vs 15.6). On update cadence, 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

Parallel Chronology is free to download; Leonhard Euler costs $1.99 up front. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

Leonhard Euler ships an update every 3 months, Parallel Chronology every 5 months. The most recent releases landed on September 25, 2026 and September 20, 2026 respectively.

Scorecard2 real differences · 8 level
Leonhard Euler versus Parallel Chronology: the parameters behind the verdict, then further details
ParameterLeonhard EulerParallel Chronology
Price$1.99Free — better
Rating—1.0 (1 ratings) — better
Positive reviews—64.3% of reviews
Number of ratings—1 — better
Update frequencyEvery 3 months — betterEvery 5 months
AdsNoNo
In-app purchasesNoNo
Monetization—Free
DevicesiPad, Mac, Apple TViPhone, iPad, iPod
Requires iOS15.613.0 — better
Further details — not scored
Size42 MB14 MB
Age rating4+12+
DeveloperVentura Educational SystemsNeusara LLC

In-app purchases

None

Leonhard Euler

No in-app purchases

None

Parallel Chronology

No in-app purchases

Questions

Is Leonhard Euler free?
Leonhard Euler costs $1.99, with no in-app purchases.
Is Parallel Chronology free?
Parallel Chronology is free to download, with no in-app purchases.
Do Leonhard Euler or Parallel Chronology have ads?
Neither Leonhard Euler nor Parallel Chronology shows ads.
Which is updated more often, Leonhard Euler or Parallel Chronology?
Leonhard Euler ships an update every 3 months, and Parallel Chronology every 5 months. Most recently, Leonhard Euler was updated on September 25, 2026 and Parallel Chronology on September 20, 2026.

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