Comparison

SigiCalc vs eigenCalc

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

eigenCalc

Features
Read full description

Matrix Calculator that computes eigenvalues and eigenvectors as well as SVD, and that has been tested with 228x228 matrices.

Screenshots

SigiCalc4 screens
eigenCalc2 screens

Verdict

The call

The clearest difference is update cadence: eigenCalc at monthly against SigiCalc's every 48 months. eigenCalc also leads on iOS requirement (15.5 vs 17.0). On price, ads, in-app purchases 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

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. Neither carries in-app purchases, so what you see is what you pay.

UpkeepUpdate frequency

SigiCalc ships an update every 48 months, eigenCalc monthly. The most recent releases landed on September 17, 2026 and October 4, 2026 respectively.

Scorecard2 real differences · 8 level
SigiCalc versus eigenCalc: the parameters behind the verdict, then further details
ParameterSigiCalceigenCalc
PriceFreeFree
Rating5.0 (1 ratings) — better—
Positive reviews50.0% of reviews—
Number of ratings1 — better—
Update frequencyEvery 48 monthsMonthly — better
AdsNoNo
In-app purchasesNoNo
MonetizationFree—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS17.015.5 — better
Further details — not scored
Size3 MB2 MB
Age rating4+17+
DeveloperSiegwareLuis Acevedo-Arreguin

In-app purchases

None

SigiCalc

No in-app purchases

None

eigenCalc

No in-app purchases

Questions

Is SigiCalc free?
SigiCalc is free to download, with no in-app purchases.
Is eigenCalc free?
eigenCalc is free to download, with no in-app purchases.
Do SigiCalc or eigenCalc have ads?
Neither SigiCalc nor eigenCalc shows ads.
Which is updated more often, SigiCalc or eigenCalc?
SigiCalc ships an update every 48 months, and eigenCalc monthly. Most recently, SigiCalc was updated on September 17, 2026 and eigenCalc on October 4, 2026.

Other comparisons