Comparison

O'der stack vs sci.calculator

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

Head to head
About

O'der stack

Features
Read full description

O'der stack is a scientific calculator that is precise for up to 38 digits and is highly flexible. It can be used for various purposes, from learning to professional use, and has many functions that are convenient when mastered. The formulas described can be saved together with the results of the calculations and easily shared among members. Also, labels and memos can be set for formulas as well as each item that makes up the formulas. For example, by adding the label "radius" to "50" in 2 x 50 x π, it is possible to make the meaning of the formula even clearer. It is also perfect for entering explanations of formulas as memos and using them as tools to assist in learning. O'der stack offers two plans, the Pro plan which offers unlimited use of all functions, as well as the Free plan which makes it usable as an easy-to-use scientific calculator. —Functions— 1. A powerful editing function that allows partial overwriting of values without erasing the formula 2. Label and memo functions to support the understanding of formulas 3. A clipboard function that allows formulas to be pasted in notebooks, etc. 4. Setting the precision of calculations from 0 digits to 38 digits 5. Setting units (degrees/radians) for trigonometric functions 6. Setting the format of displaying results of calculations (normal notation, scientific notation, and percentage notation) 7. Basic functions (exponentiation and nth root) 8. Undo function —Pro plan— Please download O'der stack and try out the Pro plan for free for seven days. In addition to all the functions in the Free plan, the Pro plan allows for the activation of even more convenient functions. 1. Functions to save and load formulas and calculation histories 2. Function to share formulas and calculation histories 3. A sub-formula function that allows for the breakdown into several formulas and simple entry 4. 18 types of versatile and widely-used functions 5. 652 highly precise numerical and physical constants and observed values 6. Setting the format of displaying results of calculations (binary, octal, hexadecimal)        - Each item can be selected from 8bit, 16bit, 24bit, 32bit, 64bit and 128bit.        - Supports negative values and decimal points.        - Negative values are displayed in complement. After the free trial has ended, if you would like to continue to use the Pro plan, a purchase of a non-autorenew-subscriptionis required. For a subscription, you can choose either a monthly purchase or yearly purchase, and the yearly purchase allows you to enjoy a discount worth two months of monthly purchases. Payment will be charged to your Apple ID account at the confirmation of purchase. If you purchase a plan during the effective period, it will be extended by the number of days of the purchased plan from the end date. The plan is effective on all devices linked to the purchased Apple ID account. Privacy policy https://ictfractal.github.io/official/PrivacyPolicy.html Terms of service https://ictfractal.github.io/official/AppTerms.pdf Disclaimer ICT Fractal Inc. does not guarantee the accuracy, credibility, and compatibility of the results of calculations and information provided through this app. Furthermore, it does not bear the responsibility for direct or indirect damages that might occur through this app.

About

sci.calculator

Features
Read full description

A stylish yet powerful scientific calculator. The app is designed with a single-screen layout for simple and intuitive operation. Calculation history is saved and can be reused easily. Results are shown in both mathematical notation and decimal format. 【Main Features】 • Basic arithmetic, modulo, trigonometric functions • Exponential, logarithmic, power and root calculations • Unit conversion and 47 scientific constants (CODEC2022) • Prime factorization, GCD and LCM • Binary, octal and hexadecimal calculations with logical operations • 8 memory slots • Permutations, combinations, and pseudo-random numbers • Systems of linear equations (up to 4 variables) • Polynomial equations (up to 4th degree) • Equation solving using Newton’s method • Time and angle calculations • External keyboard support 【Designed for Ease of Use】 • Unit conversion includes intuitive units such as “Tokyo Dome volume,” light-years, and cooking measurements. • Choose from 6 color themes to match your iPhone or iPad. • Quick switching between RAD/DEG and number bases on a single screen. • Supports iPad multitasking, allowing calculations alongside other apps. Clean, readable, and efficient. A scientific calculator that combines functionality with a modern design.

Screenshots

O'der stack4 screens
sci.calculator3 screens

Verdict

The call

The clearest difference is update cadence: sci.calculator at every 5 weeks against O'der stack's every 3 months. On price, 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

Both are free to download. O'der stack sells 3 one-off in-app purchases and sci.calculator sells 1 one-off in-app purchase. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

O'der stack ships an update every 3 months, sci.calculator every 5 weeks. The most recent releases landed on September 13, 2026 and December 22, 2025 respectively.

Scorecard1 real difference · 5 level
O'der stack versus sci.calculator: the parameters behind the verdict, then further details
ParameterO'der stacksci.calculator
PriceFreeFree
Update frequencyEvery 3 monthsEvery 5 weeks — better
AdsNoNo
In-app purchasesYesYes
DevicesiPhone, iPad, iPodiPhone, iPad, iPod
Requires iOS15.615.0 — better
Further details — not scored
Size59 MB49 MB
Age rating4+4+
DeveloperICT Fractal Inc.Yukihiro Shioya

In-app purchases

3 purchases

O'der stack

One-time3
  • Free trial for 7 days.Free
  • Activate for 1 month.$0.99
  • Activate for year.$9.99
1 purchases

sci.calculator

One-time1
  • remove Ads$1.99

Questions

Is O'der stack free?
O'der stack is free to download, with in-app purchases available.
Is sci.calculator free?
sci.calculator is free to download, with in-app purchases available.
Do O'der stack or sci.calculator have ads?
Neither O'der stack nor sci.calculator shows ads.
Which is updated more often, O'der stack or sci.calculator?
O'der stack ships an update every 3 months, and sci.calculator every 5 weeks. Most recently, O'der stack was updated on September 13, 2026 and sci.calculator on December 22, 2025.

Other comparisons