SigiCalc vs GRE Calculator
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).
GRE Calculator
Practice for the GRE Quantitative section with a calculator that mimics the restrictions of the official exam. Avoid unrealistic expectations from generic calculators by using a tool designed for accurate GRE preparation.
- Mimics official GRE exam calculator restrictions
- Realistic practice experience
- Enforces mathematical order of operations
- Handles large numbers and undefined computations
- Digit display limits and rounding
- GRE Exam Style interface
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GRE Calculator is for students preparing to give the GRE exam. The calculator offered here is one that's very similar to the one offered during a GRE exam's Quantitative section, because it follows the same operational restrictions. Other generic calculators aren't tailored specifically for GRE exam practice, which is why using them for practice isn't recommended because it gives students unrealistic expectations of what to expect during an actual GRE exam. Given below are *some* of the rules enforced by the on-screen calculator supplied during a GRE exam. GRE Calculator here follows these same rules, giving students a more realistic practice experience: 1) No exponent notations are used or allowed. 2) Use of parenthesis is allowed only to a single degree (i.e. nested parenthesis isn't allowed). 3) Any number with an absolute value larger than 99,999,999 is not displayed, and instead the phrase "Error" is displayed. 4) At any time, no more than 8 digits are shown on the screen. Rounding off is used where needed to meet this requirement. 5) Any computation performed that is mathematically undefined, results in the "Error" message being displayed. 6) Mathematical 'order of operations' is enforced. For example, if calculating 8 + 5 x 3 from left to right, the answer would be 23, not 39. ........... and there's still more! GRE Calculator also offers a style called 'GRE Exam Style', which makes the calculator look strikingly similar to the calculator offered during an actual GRE exam. This offers an even more realistic practice experience for all those using GRE Calculator.
Screenshots
Verdict
The clearest difference is rating: SigiCalc at 5.0 against GRE Calculator's 4.5. GRE Calculator's advantage is review sentiment (81% vs 50%) and ratings volume (374 vs 1). On price, ads, in-app purchases and monetization model 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. Neither carries in-app purchases, so what you see is what you pay.
SigiCalc holds the better App Store score, 5.0 against 4.5. That said, the two scores are not equally well evidenced: GRE Calculator has 374 ratings behind it against 1, so its average is the more settled of the two. Written reviews complicate that: 50% of SigiCalc's written reviews are positive against 81% of GRE Calculator's, so the app with the better star average is not the one people write more warmly about.
SigiCalc ships an update every 48 months, GRE Calculator every 24 months. The most recent releases landed on September 3, 2026 and July 4, 2026 respectively.
| Parameter | SigiCalc | GRE Calculator |
|---|---|---|
| Price | Free | Free |
| Rating | 5.0 (1 ratings) — better | 4.5 (374 ratings) |
| Positive reviews | 50.0% of reviews | 80.8% of reviews — better |
| Number of ratings | 1 | 374 — better |
| Update frequency | Every 48 months | Every 24 months — better |
| Ads | No | No |
| In-app purchases | No | No |
| Monetization | Free | Free |
| Devices | iPhone, iPad | iPhone, iPad |
| Requires iOS | 17.0 | 16.6 — better |
| Further details — not scored | ||
| Size | 3 MB | 7 MB |
| Age rating | 4+ | 4+ |
| Developer | Siegware | Ahmad Najeeb |
Customer experience
SigiCalc
GRE Calculator
Bugs and requests
SigiCalc
Not enough reviews yet to summarise bugs or requests.
GRE Calculator
Reported bugs
3 issues- Crashes when using certain functions
- Lag between button press and display
- Incompatibility with newer iOS versions
Requested features
3 requests- Web/computer version
- Tutorial for advanced functions
- Ability to use on lock screen
In-app purchases
SigiCalc
No in-app purchases
GRE Calculator
No in-app purchases
Questions
Is SigiCalc free?
Is GRE Calculator free?
Which has better reviews, SigiCalc or GRE Calculator?
Do SigiCalc or GRE Calculator have ads?
Which is updated more often, SigiCalc or GRE Calculator?
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