Comparison

SigiCalc vs RPN Big Float Calculator

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

Head to head
About

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.

Highlights
  • Graphical RPN calculator
  • Equation plotting
  • Undo functionality
  • Simple interface
  • Practical calculations
Features
Read full description

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).

About

RPN Big Float Calculator

This advanced calculator offers unparalleled precision for complex mathematical operations, supporting up to 100,000 digits. It features both RPN mode and direct formula input, with a vast array of functions and built-in constants. Explore calculations with complex numbers, quaternions, and p-adic numbers.

Highlights
  • High precision up to 100,000 digits
  • RPN and direct formula input modes
  • Complex number and quaternion calculations
  • Elliptic integrals and theta-functions
  • Built-in mathematical constants
  • P-adic number calculations
Read full description

Perhaps the most accurate calculator on the iPhone. Precision from 16-bit up to 100.000. Fast Calculation in RPN-Mode or direct formula input. Lots of functions up to elliptic integrals, theta-functions, gamma and log gamma. Built in constants for gamma, pi, Feigenbaum. Calculation mode for complex numbers, quaternions, integers and p-adic numbers. Nerdy functions with Klingon user-Interface.

Screenshots

SigiCalc4 screens
RPN Big Float Calculator1 screens

Verdict

The call

The clearest difference is update cadence: RPN Big Float Calculator at monthly against SigiCalc's every 48 months. RPN Big Float Calculator also leads on device support (4 vs 2) and iOS requirement (14.1 vs 17.0). On price, rating, review sentiment and ratings volume 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. Neither carries in-app purchases, so what you see is what you pay.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 5.0 for SigiCalc against 5.0 for RPN Big Float Calculator. Both are backed by a comparable volume of ratings — 1 and 1 respectively. Written reviews split almost evenly too, at 50% and 50% positive.

UpkeepUpdate frequency

SigiCalc ships an update every 48 months, RPN Big Float Calculator monthly. The most recent releases landed on November 1, 2026 and November 4, 2026 respectively.

Scorecard3 real differences · 7 level
SigiCalc versus RPN Big Float Calculator: the parameters behind the verdict, then further details
ParameterSigiCalcRPN Big Float Calculator
PriceFreeFree
Rating5.0 (1 ratings)5.0 (1 ratings)
Positive reviews50.0% of reviews50.0% of reviews
Number of ratings11
Update frequencyEvery 48 monthsMonthly — better
AdsNoNo
In-app purchasesNoNo
MonetizationFreeFree
DevicesiPhone, iPadiPhone, iPad, iPod, Mac — better
Requires iOS17.014.1 — better
Further details — not scored
Size3 MB14 MB
Age rating4+4+
DeveloperSiegwareStephan Jancar

Customer experience

SigiCalc

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive50.0%
Neutral0.0%
Negative50.0%

RPN Big Float Calculator

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive50.0%
Neutral50.0%
Negative0.0%

In-app purchases

None

SigiCalc

No in-app purchases

None

RPN Big Float Calculator

No in-app purchases

Questions

Is SigiCalc free?
SigiCalc is free to download, with no in-app purchases.
Is RPN Big Float Calculator free?
RPN Big Float Calculator is free to download, with no in-app purchases.
Which has better reviews, SigiCalc or RPN Big Float Calculator?
SigiCalc and RPN Big Float Calculator are both rated 5.0 out of 5 on the App Store, from 1 and 1 ratings respectively.
Do SigiCalc or RPN Big Float Calculator have ads?
Neither SigiCalc nor RPN Big Float Calculator shows ads.
Which is updated more often, SigiCalc or RPN Big Float Calculator?
SigiCalc ships an update every 48 months, and RPN Big Float Calculator monthly. Most recently, SigiCalc was updated on November 1, 2026 and RPN Big Float Calculator on November 4, 2026.

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