Hi PH 👋 I'm the maker.

Dencho started with an annoyance every calculator user knows: you do a long calculation,

one keypress is wrong, and there's no way to fix that one step — so you start over.

Dencho keeps every calculation on a tape, like a paper adding machine. The difference is

that every line is editable: tap the starting value, an operator, or an operand, and every

line below recomputes. Changed lines briefly highlight. Insert, reorder and delete lines

work the same way, and a one-tap Undo rolls the whole action back.

A few things I cared about:

• Full-precision Decimal math — amounts don't drift. Percentages follow business-calculator

rules (1000 + 8% = 1080); add-tax / remove-tax split to the yen.

• Rounding mode, decimal places and tax rate are saved per sheet — reopen an old sheet and

it reproduces exactly.

• Name a tape and it's kept as a sheet, sorted by last edited, each with its total.

• No ads, no tracking; everything stays on device. One-time $4.99 / ¥800, no subscription.

Free gives you the whole tape calculator and up to 2 saved sheets; Pro ($4.99 / ¥800,

one-time) makes sheets unlimited and adds widgets + text sharing.

It's a calculation-notes tool, not statutory bookkeeping — I'm careful about that. Happy to

answer anything, and "can it do X?" requests genuinely shape what I build next.