RPN Comp Calc vs YYi Calculator

A serious RPN calculator with a four-level stack, built the way HP taught us: ENTER, then operate. No equals key, no parentheses, no ceremony. Full scientific keyboard: trig and inverse trig (2nd key), hyperbolic functions and their inverses, logs and exponentials in every base you actually use, powers and roots, factorial and gamma, plus a curated screen of twelve physical constants (CODATA/SI-2019) one tap away. Then the part most calculators skip: a true complex-number mode. Flip to CPX and every register holds a complex value. Enter real and imaginary parts directly, see results in rectangular or polar form (r ∠ θ), and use exp, log, powers, trig and hyperbolics across the complex domain with principal-value conventions. Degrees or radians, honored everywhere. Designed for people who think in stacks: classic stack lift, roll, swap and drop; a live four-register display so you always see T, Z, Y and X; degree/radian and fixed/scientific display toggles; haptic keys. No ads. No accounts. No tracking. No network access at all. Your calculator is yours.

"I’m a developer and a dad. I built this calculator and its handy everyday tools for my family and me. Simple and easy to use on iPhone, iPad, and Mac." Personalize your calculator with rich themes and keep every calculation organized in tabs. Explore powers, roots, logarithms, trigonometry, constants, random values, memory, and parentheses. Organize work in tabs, reuse any past number, and see each tab’s total and average. Live formulas remain visible until you calculate, and the interface adapts to portrait and landscape. YYi Calculator is free: no account, ads, analytics, or tracking. Create custom themes with your own colors, font, and text size. Reuse complete formulas from history for further editing, with confirmation before replacing the current calculation. Explore a screen ruler, protractor, lighting tools and media reports in text or JSON. Use a level and magnetic compass on compatible devices. Measure distances with AR on compatible devices. Screen ruler and AR measurements are approximate; calibrate the ruler before use. Selected tools request camera or photo access; revoke it in system settings. Analysis runs on device. iCloud items may download via Apple. Reports may contain personal data; review before sharing. Feedback opens your mail app with the device model and app version prefilled; you choose whether to send. Explore uses tool visit counts and time stored on this device to arrange tools. Tool settings and measurement results also stay local. Clear history and measurements in the app; contact support for help removing other local data. These records are not sent to us. Manual order and the feedback cooldown are also saved on this device. Version highlights 1.6 • New level and magnetic compass on compatible devices. The protractor supports two-arm, single-arm and photo modes. • Reorder Explore categories and tools, and open email feedback from Support. 1.5 • Explore a screen ruler, lighting tools and media information, with text or JSON report export. • Measure distances with AR on compatible devices. Screen ruler and AR measurements are approximate; calibrate the ruler before use. 1.4 • Reuse complete formulas from history for further editing, with confirmation before replacing the current calculation. • Windows now share a single draft and history, with consistent restoration when reopening the app. 1.3 • Custom fonts and text size, plus localized Shortcuts and Siri phrases. 1.2 • Custom theme colors and a refreshed theme preset palette. 1.1 • Basic and scientific calculations, history tabs and number reuse.