Engineer's Unit Converter vs RPN Deck

A unit converter built for engineering work rather than for the kitchen. Thirty-two categories, from the everyday ones to the specialist tables you normally go looking for in a handbook: AWG wire gauge, tons of refrigeration, viscosity, water hardness, radiation dose, moment of inertia. EVERY CATEGORY, ALL FREE Length, Area, Pressure/Stress, Mass/Weight, Energy/Work, Power, Force, Torque, Volume, Temperature, Time, Speed, Angle, Data, Frequency, Fuel Economy, Density, Flow, Viscosity, Acceleration, Electric Current, Voltage, Resistance, Electric Charge, Magnetic Flux Density, HVAC Cooling, Water Hardness, Radiation Activity, Radiation Dose, Radiation Equivalent Dose, Moment of Inertia, Wire Gauge. No unlocks, no ad to watch first, no timer. Every category above is open the moment you install. ENGINEERING TOOLS An expression calculator that accepts arithmetic, fractions and scientific notation, so you can type 3/8 or 1.2e-3 straight into the field. An HVAC sizing helper that turns tons of refrigeration into BTU/h, kW and rule-of-thumb airflow. Reference tables for physical constants, thermocouple types and hardness scales. BUILT FOR THE JOB Works fully offline, so it does not care about signal on site. Reads decimal commas and points the way your region writes them. Pin the units you use, hide the ones you never touch, and reorder the rest. Add your own units with a conversion factor. Every conversion is kept in a searchable history you can tap to reuse. No account, no sign-in, no data leaves the device.

RPN Deck is a reverse Polish calculator built for speed — and for fixing mistakes without starting over. EVERY NUMBER STAYS EDITABLE On most calculators one wrong digit means clearing the lot and typing it again. Here every value stays on screen. Tap a row to correct it in place. Swipe a row away to delete it. Undo steps back through anything you did. RPN, PROPERLY Type a value, press ENTER, type the next one. No parentheses. No equals key. No expression to hold in your head and get wrong three terms later. The stack is unlimited and every level of it stays visible. FAST Four functions and a percent key. TOTAL folds the whole stack into one number in a single press. Nothing is buried in a menu, because there are no menus. THE FULL DECK — a one-time in-app purchase Three ways in, one unlock. The Tape prints every keystroke like a receipt — each entry, each operation, each total — and shares as an image, text, or PDF. Scan points the camera at a receipt so you tap printed amounts straight onto the stack. Voice lets you speak numbers and they land where you'd type them. Family Sharing is supported, so one purchase covers your family group. SIMPLE ON PURPOSE No scientific functions. One surface, and everything on it does something. PRIVATE BY DEFAULT No account. No sign-in. No analytics, no tracking, no advertising. Nothing leaves your phone unless you share it yourself. iPhone, portrait, English.