Scientific Calculator Plus 991 vs Modulo Calculator.
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
Scientific Calculator Plus 991
This app is a powerful scientific calculator with graphing capabilities, a formula library, and a unit converter. It offers natural display input, advanced math functions for algebra, calculus, and statistics, and supports various number bases and formats.
- Natural display input
- Graphing module
- Formula library
- Unit and currency converter
- Algebra and calculus tools
- Matrix and vector operations
- Statistical calculations
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NCalc — Powerful Scientific Calculator, Graphing, and Converter NCalc combines a natural-display scientific calculator, advanced math tools, a full graphing module (as 83/84 calculator), a large formula library, and a comprehensive unit and currency converter—designed for students, engineers, and anyone who loves math. ◉ Main Calculator Features - Natural display: Enter expressions exactly as in textbooks—fractions, roots, exponents, and more—see results as written on paper. - Keyboard layout: Matches popular models for familiarity and speed: 115 ES Plus, 991 ES Plus, 300 ES Plus, and 991 EX. - Symbolic and numeric modes: Perform exact fraction calculation or evaluate numerically when needed. - Arbitrary precision integers: Work with very large integers without losing accuracy. - Output types: Choose from fraction, mixed fraction, decimal, repeating decimal, degrees/minutes/seconds, and polar coordinates. - Angle units: Degree, radian, and gradian (grade). - Decimal formatter: Display numbers in normal, engineering, engineering SI, scientific, or fixed formats. - Calculation history: Review and reuse past calculations with ease. - Copy and paste support for fast data entry and sharing. ◉ Algebra, Calculus, and Core Math - Algebra calculation: Expansion, factorization, simplification, and more. - Calculus calculator: Derivatives, integrals, and limits of expressions. - Complex number calculation: Arithmetic, polar/rectangular conversion, exponential, logarithm, powers, roots, and full trigonometric functions. ◉ Equations and Inequalities - Equation solver: Solve general equations, plus dedicated solvers for quadratic, cubic, and quartic equations. - System of equations solver: Solve systems with 2, 3, or 4 variables. - Inequality solvers: Quadratic, cubic, and quartic inequalities with interval-based solutions. ◉ Matrices and Vectors - Operations: Addition, subtraction, multiplication for matrices and vectors. - Advanced tools: Determinant, inverse, transpose, rank, eigenvalues, and eigenvectors. ◉ Statistics and Distributions - Statistical calculation: Descriptive stats and regression calculation (including a regression plotter). - Distribution calculation: Normal distribution, binomial distribution, Poisson distribution, t-distribution, chi-square distribution, and F-distribution. ◉ Number Bases and Formats - Base N calculation: Effortlessly switch between binary, octal, decimal, and hexadecimal, with arithmetic in each base. ◉ Tables, Variables, and Custom Functions - Table Generator: Generate value tables based on any expression and range. - Calculator variables: Store values and reuse them across calculations. - User-defined functions: Create your own functions to streamline repetitive work. - Built-in constants: A rich set of mathematical and physical constants. ◉ Formulas - Extensive formula collection: Math and Physics formulas, clearly categorized—ideal for secondary school, high school, and university students. ◉ Unit Converter - Currency Converter - 1000+ unit conversions ◉ Graphing as 83, 84 calculator - Cartesian functions, implicit plots, polar, and parametric. - Tracing, roots, intersections, extrema, derivative, and integral evaluations on graphs. ◉ Auto-renewing subscription You may purchase an auto-renewing subscription through an In-App Purchase. • Auto-renewable subscription • Your subscription will be charged to your AppStore account at confirmation of purchase and will automatically renew (at the duration selected) unless auto-renew is turned off at least 24 hours before the end of the current period. • Current subscription may not be cancelled during the active subscription period; however, you can manage your subscription and/or turn off auto-renewal by visiting your AppStore Account Settings after purchase • Privacy policy and terms of use: https://ncalc-app.web.app/terms-of-services.html
Modulo Calculator.
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The Modulo Calculator app lets you calculate the modulo of two numbers. Modulo operation is the remainder after division of one number by another. This is often needed by programmers and computer scientists. • Short form of Modulo operation is mod and the symbol is %. • Support for exponential notation (^ power) • Support for calculations including: inverse (^-1), addition, subtraction, multiplication and division • Support for decimal numbers • See how the modulo operation result differs between different modulo definitions used by programming languages • Supported modulo definitions: Euclidean Modulo, Truncated Modulo and Floored Modulo • See how many times the second number fits in the first one • Lets you copy the result to your clipboard • Light and dark mode
Screenshots
Verdict
The clearest difference is in-app purchases: Modulo Calculator. at none against Scientific Calculator Plus 991's 4. Modulo Calculator. also leads on iOS requirement (12.0 vs 15). Scientific Calculator Plus 991's advantage is update cadence (fortnightly vs every 4 months). On price, 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
Both are free to download. Scientific Calculator Plus 991 sells 4 in-app purchases, starting at $1.99 per month. Modulo Calculator. asks for nothing beyond the download.
Scientific Calculator Plus 991 ships an update fortnightly, Modulo Calculator. every 4 months. The most recent releases landed on November 11, 2026 and November 6, 2026 respectively.
| Parameter | Scientific Calculator Plus 991 | Modulo Calculator. |
|---|---|---|
| Price | Free | Free |
| Rating | 4.7 (13K ratings) — better | — |
| Positive reviews | 91.8% of reviews | — |
| Number of ratings | 13K — better | — |
| Update frequency | Fortnightly — better | Every 4 months |
| Ads | Yes | Yes |
| In-app purchases | Yes | No — better |
| Monetization | Free with in-app purchases | — |
| Devices | iPhone, iPad, iPod, Mac — better | iPhone, iPad, iPod |
| Requires iOS | 15 | 12.0 — better |
| Further details — not scored | ||
| Size | 169 MB | 29 MB |
| Age rating | 12+ | 4+ |
| Developer | Tran Duy | Milos Lukas Ziolkowski |
Bugs and requests
Scientific Calculator Plus 991
Reported bugs
3 issues- Keyboard input stops working after switching screens
- Incorrect calculation results for certain operations
- App crashes on some devices after recent update
Requested features
5 requests- Add option to change display font and color
- Improve cursor control and editing capabilities
- Implement auto-simplification for complex expressions
- Add more handwriting font options
- Expand graphing and equation solving features
Modulo Calculator.
Not enough reviews yet to summarise bugs or requests.
In-app purchases
Scientific Calculator Plus 991
- Calculator month subscription$1.991 Month
- Calculator yearly subscription$3.991 Year
- Calculator Premium$5.99
- Calculator Pro$5.99
Modulo Calculator.
No in-app purchases
Questions
Is Scientific Calculator Plus 991 free?
Is Modulo Calculator. free?
Do Scientific Calculator Plus 991 or Modulo Calculator. have ads?
Which is updated more often, Scientific Calculator Plus 991 or Modulo Calculator.?
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