GraphCalc 84: Graphing Calc

A full graphing calculator with the layout and feel of a classic handheld — built for iPhone and iPad. Plot up to 9 equations, run TI-style programs, solve systems, fit regressions. No ads, no subscriptions, no internet required. GraphCalc 84 is the classic graphing calculator, rebuilt for your phone — complete, faithful, and fast. If you know the TI-84, your muscle memory works on day one. Graph everything. Function, parametric, polar, and sequence modes with nine equation slots, trace, tables (Auto or Ask), zoom — including ZoomStat — and full window control. Find zeros, minima, maxima, intersections, derivatives, and integrals right from the CALC menu. Statistics, complete. Every hypothesis test and confidence interval — Z, T, 2-sample, proportions, χ², χ²-GOF, F, LinRegTTest, ANOVA — plus 1-Var/2-Var Stats and 13 regression models with TI-accurate quartiles. Visualize with scatter, xyLine, histograms, box-and-whisker, and normal probability plots, and shade distribution areas right on the graph. Real fractions with ►Frac/►Dec and mixed-number display. Number bases from binary to hex with bitwise operators. Your AI tutor (new in 1.7). Long-press any answer — or any error — for a clear step-by-step explanation. Ask for worked steps when a problem is beyond the built-in solver. Have your graphs described in plain language, from intercepts to asymptotes, computed by the calculator and narrated by AI. All AI features are optional: bring your own Anthropic API key, keep it securely on your device, and send nothing until you choose to. Without a key, GraphCalc 84 remains complete and fully offline. Exact where you want it (new in 2.0). Switch ANSWERS mode to Auto and results stay mathematically exact — fractions, simplified radicals, multiples of π — with ►Dec one press away. Four symbolic commands bring real algebra: simplify, expand, factor with exact roots, and derivatives. Prefer decimals? Everything stays exactly as it was until you opt in. Programmable. Write and run TI-BASIC programs — control flow, input/output, and the complete DRAW command set, down to reading pixels with pxl-Test(. Beyond the original. A physical-units engine with dimensional analysis. Math Snap: point your camera at a problem, or write it by hand. A hub of 22 built-in apps — solvers, periodic table, physics constants, curve fitting, date math, and more. Twelve accessibility-tested themes, with a free web editor to design your own. GRAPHING • Function, parametric, polar, and sequence modes • 9 simultaneous equations, color-coded • ZOOM (in/out, decimal, square, standard, trig, fit), TRACE with touch-jump • CALC: zeros, min/max, intersect, dy/dx, ∫f(x)dx • Spiffy Graph mode — neon glow with adjustable intensity MATH • Trigonometry, logarithms, complex numbers (rectangular & polar) • Matrices [A]–[J] with full linear-algebra ops • Statistics: 1-Var, 2-Var, ten regression types including SinReg • Distributions: Normal, t, χ², F, Binomial, Poisson, Geometric • Probability: nPr, nCr, factorial, randInt, randNorm, randBin APPS • TVM Solver, Loan Calculator, Tip Split • Equation Solver, Quadratic, Polynomial Roots, Systems • Numerical derivative, definite integral, Riemann Explorer • Periodic Table, Physics Constants, Coordinate / Unit Converter • Curve Fitting, Combinatorics, Dice Probability • Date Calculator, Vector Calculator, Step-by-Step Solver, Graph Inequalities PROGRAMMING • BASIC-style language with If/Then/Else, While, For, Repeat • Draw, Line, Circle, Shade, Text, StorePic / RecallPic • Programs persist across launches PERSONAL • 12 themes including amber phosphor, green phosphor, midnight, paper, porcelain, sunset — all WCAG-AA contrast certified • External display support on iPad • Hardware keyboard support • Imports custom .gctheme.json files WHY GRAPHCALC 84 • Buy once. Free updates. No ads. No subscriptions. • Every calculation runs on-device. No account, no telemetry.