Sumi: Tape Calculator

Never lose track of your math. Sumi keeps every line on a running tape you can edit, annotate, and total instantly — on iPhone, iPad, and your Mac menu bar.

Sumi is a calculator that remembers.

Instead of a single number that disappears the moment you hit equals, Sumi shows your whole calculation as a running tape — every line visible, editable, and adding up to a live total. It's the fast, frictionless way to work through anything from a quick estimate to a full list of expenses.

A CALCULATOR WITH A MEMORY • Every entry stays on screen as a scrollable history tape • A live Total updates as you go — no re-typing • Operators are color-highlighted so long expressions stay readable

EDIT ANYTHING, ANYTIME • Tap any line to move the cursor and fix a number • Recalculate instantly without starting over • Use parentheses and full operator support for real expressions

ADD NOTES THAT STICK • Label any line with a note — "rent", "tax", "client A" • Notes appear as clean tags right next to the math • Finally know what each number was for

SHARE YOUR WORK • Copy the whole tape as text • Share a clean screenshot of your history • Perfect for sending a quick breakdown to someone

LIVES WHERE YOU WORK • A tidy app on iPhone and iPad • A menu bar calculator on Mac — one click away, always there • The same calculator, wherever you are

MAKE IT YOURS • Choose from beautiful themes • A calm, focused design that gets out of your way

PRIVATE BY DESIGN • Everything happens on your device • No accounts, no tracking, no clutter

Great for budgets, receipts, invoices, splitting bills, expense tracking, and any time one number just isn't enough.

Download Sumi and never lose your train of thought mid-calculation again.