Scientific Calculator Plus 991 Downloads & RevenueScientific Calculator Plus 991 · App Store
Scientific Calculator Plus 991 is #101 in Education Free in Germany and charting in 4 of 30 countries we track.
Updated 12 Nov 2026 · rankings refresh through the day
DeveloperTran Duy
CategoryEducation
PriceFree
Released
Rating★ 4.7 (5.7k)
Version3.6.6
Age rating12+
First seen by us
25 Sep 2026
25 Sep 2026Installs (est.)10M+ worldwide
Scientific Calculator Plus 991 update history & changes
Last change · 21 events since 3 Apr 2019Full timeline ↓🔎#1 for “calculator”📈Entered the top 100📦Updated to version 3.6.6⭐Passed 10K ratings🔎Top 10 for “calculator”📦Updated to version 3.6.2⭐Passed 10K ratings📈Entered the top 100🆕First spotted by AppInsider🆕Released on the App Store
Full timeline · 21 events
- 🔎Scientific Calculator Plus 991 reached #1 for “calculator”#1 in Malaysia search · popularity 68
- 📈Scientific Calculator Plus 991 entered the top 100Top Free · Education · DE
- ✏️Scientific Calculator Plus 991: app got smaller218 MB → 177 MB (-19%)
- 📦Scientific Calculator Plus 991 updated to version 3.6.6- Customise key sounds, volume and vibration, and choose separate fonts for the keyboard and display.
- Equation solver: find more roots and view equations and inequalities on a graph.
- Camera: frame and zoom in on an expression, with the photo kept visible during recognition.
- Preview Normal, FIX, SCI and ENG formats and choose how many digits to show.
- History keeps your BASE-N and SOLVE calculations.
- Matching brackets are highlighted and grow to fit fractions. Tap the display arrows to scroll long expressions.
- Browse 47 scientific constants by category in CONST.
- Fixed the order of user-defined functions after rearranging them.… more - ✏️Scientific Calculator Plus 991: app got bigger184 MB → 218 MB (+18%)
- 🔎Scientific Calculator Plus 991 reached Top 10 for “calculator”#10 in United States search · popularity 75
- 📦Scientific Calculator Plus 991 updated to version 3.6.2- Inequalities: get the full answer, now in interval notation.
- Tap a result to see it in other forms, save it to a variable or open it as a table.
- New themes: Blueprint, Paper, Synthwave and Solarized.
- Camera: scan, compute or draw an expression.
- Copy an expression as LaTeX or as an image.
- The user manual is now available in your language.… more - 📦Scientific Calculator Plus 991: first update in 111 days
- 📈Scientific Calculator Plus 991 entered the top 100Top Free · Education · GB
- 📈Scientific Calculator Plus 991 entered the top 100Top Free · Education · AE
- 🔎Scientific Calculator Plus 991 reached Top 10 for “calculator”#6 in Indonesia search · popularity 73
- 📈Scientific Calculator Plus 991 charting in a new countryIndia
- 🔎Scientific Calculator Plus 991 reached Top 10 for “calculator”#10 in Taiwan search · popularity 74
- 📈Scientific Calculator Plus 991 charting in a new country in 2 chartsUnited Kingdom · Indonesia
- 📈Scientific Calculator Plus 991 entered the top 100Top Free · Education · SA
- 📈Scientific Calculator Plus 991 charting in a new countrySaudi Arabia
- 🆕Scientific Calculator Plus 991 first spotted by AppInsider#51 in Top Free · Education · Germany
- 📦Scientific Calculator Plus 991 version 3.6.1Thanks for using NCalc! This update includes performance improvements, stability enhancements, bug fixes, UI refinements, and compatibility updates for the latest iOS versions to ensure a smoother, more reliable experience.… more
- 🆕Scientific Calculator Plus 991 released on the App Store
Collected from the stores by AppInsider since we first spotted the app. Dates are when we saw each change.
Rating
4.7 ★
5.7k ratings
Measured
Best rank now
#101
Education FreeMeasured
New ratings a week
32
▲ +11% vs the 2 weeks before
Measured
Scientific Calculator Plus 991 on the App Store
App details
App ID
1449106995
Publisher
Tran Duy
On the store since
Apr 2019
7 years on the store
Minimum OS
iOS 15+
iPhone 6s and later
Devices
iPhone · iPad
Universal purchase
Content rating
12+
3 content notes below
Languages
51
SQ AR HY AZ EU BE BN BS BG CA HR CS …
Size
177 MB
Also listed in
Productivity
Content notesInfrequent/Mild Mature/Suggestive ThemesInfrequent/Mild Realistic ViolenceInfrequent/Mild Cartoon or Fantasy Violence
Scientific Calculator Plus 991 downloads
Worldwide, per day, and installs to date. The band is open; the exact number is free with an account.
How this is calculated
Apple publishes no download counts. App Store downloads come from chart positions and daily rating growth per country, calibrated on Google Play install counts; lifetime installs from ratings worldwide × installs per rating. Confidence is the chance the real number is within half to double ours.
Where Scientific Calculator Plus 991's downloads come from Modelled
Last 30 days: organic search, browsing the store, features and paid ads.
Active users
All platforms, worldwide. Free with an account.
Stickiness (DAU / MAU)
how many monthly users open it on a given day
Retention · share of new users still active
Day 1
Day 7
Day 30
Time spent · per daily user
Average time spent Pro
min a day
Sessions a day Pro
Time per session Pro
min
How this is calculated
Monthly users come from lifetime installs across every store, fitted on monthly active user figures companies publish; daily users = monthly × the typical daily/monthly ratio for the category. Confidence is the chance the real number is within half to double ours.
In-app revenue
Worldwide, what users spend in Scientific Calculator Plus 991 before Apple and Google take their fee.
How this is calculated
Not on any Top Grossing chart: monthly active users × spend per user for its category, measured on the charted apps nearest the bottom of the charts.
Business model: Subscription-led
How Scientific Calculator Plus 991 makes money: subscriptions, one-off purchases and ads.
SubscriptionsIn-app purchases
Subscriptions
/mo
of revenue
Top in-app purchases · App Store US, most popular first
| 1 | Calculator Premium subscription | |
| 2 | Calculator month subscription subscription | |
| 3 | Calculator yearly subscription subscription | |
| 4 | Calculator Pro subscription |
Where it ranks now
Every top chart it appears in across 30 countries.
| Country | Charts | Rank |
|---|---|---|
| Germany | EducationFree | #101 |
 United Kingdom | EducationFree | #196 |
 Saudi Arabia | EducationFree | #92 |
 Indonesia | EducationFree | #162 |
Apps near Scientific Calculator Plus 991 on the chart
Education Free, around #101.
Ratings
App Store, worldwide.
Rating
4.7 ★
5.7k ratings
Measured
Ratings
5.7k
Measured
Review momentum
ⓘ How we measure thisNew ratings a week
32
▲ +11% vs the 2 weeks before
Lifetime rating
4.7★
recent stars not readable yet: new ratings are a tiny share of the total
Review momentum
76/100
faster than 91% of Education apps
Growing fastest in Saudi Arabia ▲ +75%
New ratings by country (5)
| Country | New ratings a week | Share | Last 2 weeks vs the 2 before |
|---|---|---|---|
| Saudi Arabia | 11 | 33% | ▲ +75% |
| Germany | 9 | 28% | ▼ -10% |
| United Kingdom | 8 | 25% | steady |
 United Arab Emirates | 3.5 | 11% | ▼ -40% |
| Indonesia | 1.2 | 4% | – |
App Store ratings in the countries we track, 4-week average.
Review momentum (0-100) blends how fast the app collects ratings compared with other apps in its category (60%), whether that pace is speeding up (25%) and what recent raters give it (15%; recent stars well below lifetime pull it down). Ratings counts are read daily. A jump usually means a launch, a feature, ads or a new review prompt.
About Scientific Calculator Plus 991
NCalc — Powerful Scientific Calculator, Graphing, and Converter
NCalc combines a natural-display scientific calculator, advanced maths 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 maths.
◉ 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 calculations or evaluate numerically when needed.
- Arbitrary‑precision integers: Work with very large integers without losing accuracy.
- Output types: Choose from fraction, mixed fraction, decimal, recurring 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 Maths
- Algebra calculations: Expansion, factorisation, simplification, and more.
- Calculus calculator: Derivatives, integrals, and limits of expressions.
- Complex number calculations: Arithmetic, polar/rectangular conversion, exponential, logarithms, 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‑squared 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‑ins and Help
- Built‑in constants: A rich set of mathematical and physical constants.
- Built‑in documentation: Access helpful guidance anytime via the Help button.
◉ Formulae
- Extensive formulae collection: Maths and Physics fo
NCalc combines a natural-display scientific calculator, advanced maths 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 maths.
◉ 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 calculations or evaluate numerically when needed.
- Arbitrary‑precision integers: Work with very large integers without losing accuracy.
- Output types: Choose from fraction, mixed fraction, decimal, recurring 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 Maths
- Algebra calculations: Expansion, factorisation, simplification, and more.
- Calculus calculator: Derivatives, integrals, and limits of expressions.
- Complex number calculations: Arithmetic, polar/rectangular conversion, exponential, logarithms, 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‑squared 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‑ins and Help
- Built‑in constants: A rich set of mathematical and physical constants.
- Built‑in documentation: Access helpful guidance anytime via the Help button.
◉ Formulae
- Extensive formulae collection: Maths and Physics fo
Latest updates
3.6.6
- Customise key sounds, volume and vibration, and choose separate fonts for the keyboard and display.
- Equation solver: find more roots and view equations and inequalities on a graph.
- Camera: frame and zoom in on an expression, with the photo kept visible during recognition.
- Preview Normal, FIX, SCI and ENG formats and choose how many digits to show.
- History keeps your BASE-N and SOLVE calculations.
- Matching brackets are highlighted and grow to fit fractions. Tap the display arrows to scroll long expressions.
- Browse 47 scientific constants by category in CONST.
- Fixed the order of user-defined functions after rearranging them.
3.6.2
- Inequalities: get the full answer, now in interval notation.
- Tap a result to see it in other forms, save it to a variable or open it as a table.
- New themes: Blueprint, Paper, Synthwave and Solarized.
- Camera: scan, compute or draw an expression.
- Copy an expression as LaTeX or as an image.
- The user manual is now available in your language.
3.6.1
Thanks for using NCalc! This update includes performance improvements, stability enhancements, bug fixes, UI refinements, and compatibility updates for the latest iOS versions to ensure a smoother, more reliable experience.
Store changes
What Scientific Calculator Plus 991 changed on its store page: name, icon, screenshots, price, size, languages, requirements.
App got smaller
218 MB → 177 MB (-19%)
App got bigger
184 MB → 218 MB (+18%)
