Launched this week
Dencho
The tape calculator you can edit — fix a line, it recomputes
12 followers
The tape calculator you can edit — fix a line, it recomputes
12 followers
A calculator that keeps its working on a tape you can edit. Tap any line — value, operator, or operand — and everything below recomputes. Full-precision Decimal, per-sheet rounding & tax, named sheets with totals. One-time $4.99 / ¥800, no ads, on-device.
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.
https://apps.apple.com/app/id6789548710
A paper tape you can actually edit is such a natural idea, kind of surprised it isn't standard everywhere. One thing I'd love: export the sheet as a CSV with the formulas intact, not just the final numbers. That way I can drop a working version straight into Sheets or Numbers and keep auditing it later.
@rojinbalarman
Thanks — this is a useful one, and more specific than most feature asks.
To be straight about what exists today: Dencho's sharing (Pro) gives you the sheet as formatted text with the note lines intact, so it pastes anywhere — but the numbers land as values, not as anything a spreadsheet can recompute.
What you're describing is better than plain CSV: each tape line written as a formula that references the line above (so a "+1,250" line becomes something like =B3+1250), which keeps the whole calculation live and auditable in Sheets or Numbers. That maps cleanly onto how the tape already works internally, so it's a fair bit of work but not a strange fit.
Honestly, I left CSV out of v1 because I hadn't seen anyone actually ask for it. This is the first concrete request, and it's the right kind — so it goes on the list. No promises on timing.
One question, if you don't mind: would you want the sheet's rounding mode and tax rate carried across too? That's the part where a spreadsheet and a business calculator quietly disagree, and I'd rather know which behavior you'd expect before building it.
Tap to edit a past line and watch the total update feels almost too satisfying. Love that it stays on device with no ads.
@hafizeokudur
Thank you — that "edit a past line and the total just moves" moment is the whole reason the app exists, so I'm glad it lands. Insert, reorder and delete work the same way, and one Undo rolls the entire action back if you overshoot.
On-device with no ads was deliberate: a calculation tape ends up holding fairly personal numbers, so it stays on the phone.