SigiCalc

RPN Graphing Calculator

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).