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For saleWorking prototype

GhostCalc

A real working spreadsheet with a ghost in it. It changes your numbers, then writes about it in its diary.

Screenshots

  • A blue text-mode spreadsheet of household accounts under black light, with the ghost's changes glowing pink and its diary beside them
  • The spreadsheet and formula bar on a phone
  • The sheet restored, with crossed-out diary entries and a CSV copy below

Screenshots supplied by the seller.

Open demo (opens in a new tab)

Description

GhostCalc is a proper little spreadsheet that happens to be haunted. Type numbers, write formulas, build a budget. Then, every so often, a pixel ghost drifts across the grid and quietly changes something. It might move a few pounds out of a cell, swap two numbers, shorten a total by one row, or leave a note saying "i was an auditor".

You can fight back. Salt up to six cells and the ghost can't touch them. Switch on the black light to see everything it has changed glowing pink. Its diary lists each trick in its own words, with a Put back button beside each one, and one big button undoes the lot without disturbing your own edits.

The ghost has three moods: Asleep, Restless and Poltergeist. Two formulas exist just for it. =GHOST() counts the hauntings, and =ASK("will it balance") gets you a straight answer from beyond the grave.

Underneath the joke is a real spreadsheet engine with cell references, ranges, SUM, AVERAGE, MIN, MAX, COUNT, ROUND, ABS and IF, loop detection and clear error messages. It's styled like a 1986 text-mode office program. Plain HTML, CSS and JavaScript with no server or running costs, and a good fit for April Fools, a viral toy or a joke gift for an accountant.

Condition

Development stage: Working prototype (seller-declared)

Seller-declared: provided by the seller, not independently verified by SellMyVibe.

  • Solo creator
  • Mainly AI-generated
  • Under one month in development
  • Mobile-friendly
  • Tests included
  • Setup guide included
  • Demo available

What works

  • 8 by 24 grid with keyboard navigation and a formula bar
  • Formulas with references, ranges, operators and percentages
  • SUM, AVERAGE, MIN, MAX, COUNT, ROUND, ABS and IF
  • Clear errors for loops, division by zero, bad names and bad formulas
  • Ghost that nudges numbers, swaps cells, shortens sums and leaves notes
  • Three ghost moods, from Asleep to Poltergeist
  • Salt to protect up to six cells
  • Black light that shows every cell the ghost changed
  • Diary with Put back on each entry and Put everything back
  • =GHOST(), =ASK() and =BOO() formulas
  • Copy your sheet out as CSV
  • Sheet remembered between visits
  • 17 tests covering formulas, the ghost, salt and restoring the sheet

What’s unfinished

  • One sheet only, with a fixed 8 by 24 grid
  • No copy and paste of cell ranges, and formulas don't adjust when moved
  • No CSV import, charts or number formatting
  • Touch use hasn't been tried on a real phone. On a phone you tap a cell, then tap the formula bar to edit

Included assets

Full source code

Test suite

Documentation

Technologies

HTML, CSS, JavaScript (ES modules), localStorage, Node test runner

Setup requirements

Upload the files to any static web host. To try it locally, run python3 -m http.server and open http://localhost:8000. Run the tests with npm test (Node 20 or newer).

Dependencies and ongoing costs

None. It's a static site that runs free on any web host and uses system fonts.

Known limitations

This is a joke product with a real engine, so it isn't meant for real accounts. The ghost really does change your numbers unless you set it to Asleep. The sheet is stored in one browser only.

Listings are reviewed for completeness and clarity before publication. Approval is not a guarantee of quality, ownership, security or commercial success. Read the details and ask questions before buying.