wtf is bindery?

Bindery is a mobile app that bundles a set of PDF editing tools together, built with the specific goal of never needing an internet connection. The app's permissions do not include internet access at all, so every operation, from merging files to converting images, runs directly on the phone's own processor. Nothing is uploaded anywhere, and there is no analytics or tracking of any kind. Its most detailed feature is a booklet maker, which turns a regular PDF into a foldable booklet layout suitable for printing and binding. It supports splitting a thick document into multiple signatures of 8, 16, or 32 pages each, several standard paper sizes, both short and long edge duplex printing, right to left binding for languages that read that direction, and a separate export for a heavier cover page. It can also insert blank pages at chosen spots and print an instruction sheet that checks the reading order came out correctly, and it includes an interactive animation that folds a page in 3D to explain what a signature actually is. Beyond the booklet tool, Bindery can merge multiple PDFs into one, add, delete, and reorder pages, rotate pages, add page numbers, and add watermarks. It can also turn photos into a PDF, automatically correcting the perspective so a photographed document looks flat. A built in PDF reader offers a night mode that inverts colors intelligently rather than just darkening the screen, lets you select and copy text, search inside a document, and pick back up automatically at the last page you were reading. Files can also be organized and sorted from within the app. The project is built with TypeScript and uses Capacitor to package a web based app for Android devices, with its own test and build scripts for developers who want to compile it themselves. It is released under the GPL-3.0 license, a copyleft license that requires anyone who distributes a modified version to release their changes under the same terms.