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KDP Spine & Formatting Calculator

Chrome extension by PrinceLucie · Productivity · Tools

A Chrome extension in Productivity · Tools with 4 users, barely installed.

Specific sites only: 1 match pattern.

What the developer says, and 3 screenshots

Loading from the Chrome Web Store. Open the listing if it does not appear.

Users
4
Rating
not rated yet
Users, last 15 days
+4
Version
1.0.0
Updated in the store
2026-07-20
Published
2026-07-20
Manifest
V3
Browser access
1 permission, 1 site pattern

How it has moved

Users
+4 since 01.09
0-4 · 6 readings
  1. 2026-09-010
  2. 2026-09-023
  3. 2026-09-054
  4. 2026-09-084
  5. 2026-09-093
  6. 2026-09-154
Users
+4 since 01.09
0-4 · 6 readings
  1. 2026-09-010
  2. 2026-09-023
  3. 2026-09-054
  4. 2026-09-084
  5. 2026-09-093
  6. 2026-09-154

A dot marks a day the store showed a different number. Between them the line carries the last one forward: we read every listing more than once a day and record a point only when something moves. History beyond ninety days is in the app.

What it can reach

Specific sites only: 1 match pattern.

  • https://api.gumroad.com/*
  • Store data in your browser storage

The full permission history for this extension

What changed recently

Nothing has moved on this listing since we started watching it.

The publisher

PrinceLucie publishes 3 listings we track, 12 users between them.

  1. KDP Royalty Ledger PrinceLucie · Productivity · Tools · published 2026-07-22 5 users
  2. ResaleInv — listing helper PrinceLucie · Productivity · Workflow · published 2026-09-04 3 users

Like this one

Listings the catalog judges closest in what they say they do.

  1. KDP Template Overlay Describes nearly the same job, smaller audience 23 users
  2. KDP Launch Check Describes nearly the same job, smaller audience 3 users
  3. Photo Print Layout Describes nearly the same job, smaller audience 36 users
  4. dummyPDF Generator Describes a similar job, smaller audience 31 users ★ 5.0
  5. Bookshot — Instant Book Mockups Describes a similar job, smaller audience 4 users

The top 5 only. The full comparison, with why each one is close, is on the alternatives page; ranking a whole neighbourhood by your own criteria is in the app.

Is this your extension?

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See what the panel does

Figures come from our own daily pass over the public Chrome Web Store listing, last read on . We publish no contact details for extension developers.