SigiCalc vs GT Graph
Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.
SigiCalc
This app provides a graphical RPN calculator with an undo feature. Users can input mathematical equations and instantly visualize them with a plot. It's designed for simplicity and practicality in mathematical calculations.
- Graphical RPN calculator
- Equation plotting
- Undo functionality
- Simple interface
- Practical calculations
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SigiCalc is a fast, clean RPN calculator that draws your functions. Enter a calculation the RPN way – numbers first, then the operation – and as soon as your expression contains X, tap Graph to see it plotted. No equals key, no parentheses, no fuss. REAL RPN • Classic stack-based entry with Enter, Undo and All Clear • Keys light up only when the stack has enough values – you can't make an invalid entry • The display shows your result, the whole expression in normal notation and the raw stack LIVE FUNCTION GRAPHS • Use X as a variable and plot the result instantly • Pinch to zoom, drag to pan, tap to zoom in, double-tap to reset • Touch and hold to read the exact x / y value on the curve • Discontinuities like tan(x) or 1/x are drawn correctly – no misleading vertical lines SCIENTIFIC FUNCTIONS sin, cos, tan and their inverses, natural log, square, square root, reciprocal, sign change and π DESIGNED FOR TODAY'S DEVICES • Light and Dark Mode, portrait and landscape • iPad: calculator and live graph side by side • Smooth animations and haptic feedback PRIVATE BY DESIGN SigiCalc works entirely on your device. No account, no network, no ads, no tracking. Example: X ↲ X sin × plots x · sin(x). What changed versus your text and why: - Leads with a benefit, not a category: "draws your functions" is the hook; "simple and practical graphical" told the reader nothing they'd search for. - Explains RPN in one sentence for people who don't know it, since that's the biggest reason someone bounces. - Bulleted feature blocks — App Store descriptions are skimmed, and the capitalised headings scan well in the store's plain-text rendering. - Adds Dark Mode / iPad / privacy, all of which are new in 3.0 and are things reviewers and users look for. - Fixed "polish" → "Polish" and "equation" → "expression" (you plot expressions, not equations).
GT Graph
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GT Graph transforms your device into a powerful mathematical visualization tool. Plot equations, explore calculus concepts, and bring mathematics to life with stunning interactive graphs. PLOT ANY EQUATION - Cartesian functions - Polar curves - Parametric equations - Implicit equations - Inequalities with shaded regions INTUITIVE INPUT Type equations naturally with implicit multiplication support. Write 2x instead of 2*x, or 2sin(x) instead of 2*sin(x). GT Graph understands mathematical notation the way you write it. COMPREHENSIVE FUNCTION LIBRARY - Trigonometric: sin, cos, tan, sec, csc, cot - Inverse trigonometric: asin, acos, atan - Hyperbolic: sinh, cosh, tanh - Exponential and logarithmic: exp, ln, log, log2 - Power functions: sqrt, cbrt, abs - Constants: pi, e, phi (golden ratio) MULTIPLE GRID TYPES - Standard Cartesian grid - Trigonometric grid with pi-labeled axes - Polar coordinate grid with radial lines - Logarithmic scale grid CALCULUS TOOLS - Calculate derivatives at any point - Compute definite integrals with visual shading - Find zeros (roots) of functions - Locate local minima and maxima - Generate value tables INTERACTIVE EXPLORATION - Pinch to zoom, drag to pan - Tap to show tangent lines - Crosshair cursor displays coordinates - Plot multiple equations simultaneously - Color-coded graphs for easy identification SAVE AND SHARE - Save your work as .gtgraph files - Export and share with colleagues - Equation history saves your last 25 entries - Settings persist between sessions Perfect for: - Students learning algebra, trigonometry, and calculus - Teachers creating visual demonstrations - Engineers and scientists visualizing data - Anyone curious about mathematical beauty GT Graph combines the power of professional graphing software with the elegance of modern design. Start plotting today!
Screenshots
Verdict
The clearest difference is in-app purchases: SigiCalc at none against GT Graph's 1. GT Graph's advantage is update cadence (every 8 days vs every 48 months). On price, ads, device support and iOS requirement 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. GT Graph sells 1 one-off in-app purchase. SigiCalc asks for nothing beyond the download.
SigiCalc ships an update every 48 months, GT Graph every 8 days. The most recent releases landed on October 13, 2026 and October 8, 2026 respectively.
| Parameter | SigiCalc | GT Graph |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | — |
| Positive reviews | 50.0% of reviews | — |
| Number of ratings | 1 — better | — |
| Update frequency | Every 48 months | Every 8 days — better |
| Ads | No | No |
| In-app purchases | No — better | Yes |
| Monetization | Free | — |
| Devices | iPhone, iPad | iPhone, iPad, Mac — better |
| Requires iOS | 17.0 — better | 18.0 |
| Further details — not scored | ||
| Size | 3 MB | 1 MB |
| Age rating | 4+ | 4+ |
| Developer | Siegware | Gennaro Eduardo Tangari |
In-app purchases
SigiCalc
No in-app purchases
GT Graph
- GT Graph In-App Purchase$0.99
Questions
Is SigiCalc free?
Is GT Graph free?
Do SigiCalc or GT Graph have ads?
Which is updated more often, SigiCalc or GT Graph?
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