Winston: Maths Calculator

One purchase, no subscription: scientific calculator, graphing, distributions, matrices, RPN and programmer modes. New: backups, CSV export and Siri Shortcuts.

Winston is a scientific calculator, graphing calculator and math workbench that runs entirely on your iPhone or iPad. Pay once: no subscription, no ads, no account and no network connection.

NEW IN 4.0 • Probability distributions: normal probabilities and inverse normal, Student's t, binomial and Poisson, with P(X = k), P(X ≤ k) and P(X ≥ k). • Backup and restore: save your history, A–Z registers, memory, preferences and comparison worksheet to a file. Restore it on another device, and undo a restore if you change your mind. • CSV export of your calculation history. • Siri and Shortcuts: the Calculate Expression action returns a result without opening the app. • Quartiles and IQR in Statistics. • Exact trig at quarter turns (sin 180° = 0; tan 90° is undefined) plus many other accuracy fixes.

CALCULATE A scientific keypad with history, Ans, memory and A–Z variable registers. Implicit multiplication such as 2πr or sin(πx). Radians, degrees and gradians. Factorials, combinations, permutations, logarithms in any base, and hyperbolic functions.

GRAPH AND ANALYZE Plot one or two functions, then pinch, pan and trace to find roots, extrema, inflection points and intersections. Function Lab reports derivatives, an adaptive integral with an error bound, roots and inflection points.

MORE TOOLS • Matrix Lab with worked row steps, determinant, inverse and eigenvalues • Equation, polynomial and linear-system solvers • RPN stack calculator • Programmer mode: hex, decimal, octal and binary at 8 to 64 bits • Fractions and complex numbers • Statistics and linear regression • Compare two models at the same inputs • Result Audit, which checks angle mode, domain-sensitive functions and sensitivity to input rounding • Unit converter, CODATA 2022 physical constants and a formula library

WHAT TO KNOW Results use double-precision floating point, about 15 to 16 significant digits. Graph features and sampled comparisons are numerical and do not prove exact values between samples. Distributions describe the model you enter. Works on iPhone and iPad.