About
Peregrin is an ebook reading application for the gpub ebook format. It is intended to be used on mobile devices as a "progressive web app" (PWA). If you have not already: you can install it from your mobile browser. In your browser's menu there should be an option to "install" or "add to home screen". This will let it run as a standalone application in full screen mode.
This application imports and keeps your books in browser storage (once imported, you may delete them from your hard drive or sd card), for which there is a storage limit of 5–10MB (you can check your current usage on the settings page). You can read and add books fully offline. Peregrin does not make any outside network requests (unless you follow a link in a book to an outside resource) and does not do any kind of tracking or usage metrics.
Usage
From the main library screen you can add a book by tapping "Browse" or "Upload a New Book". Select a gpub formatted document from your hard drive or sd card.
Once you have added a book it will appear in your book list. Tap a book's name and you will be taken to the reader page. Swipe left and right to navigate pages. Tap in the middle to bring up or close the menu bar (from which you can get metadata, navigate via the table of contents, or go back to your book list). If the application is being run on a system with a dedicated keyboard arrow left and arrow right can also navigate pages and the escape key will toggle the menu open and closed.
Settings are accessible from the main book library screen as a link at the bottom. You can set light/dark mode, font size, and whether to keep the screen awake. You may also view how much storage you have used.
Requirements
This application has been tested on Firefox for desktop Linux (Debian) and Firefox for Android (on an old LG Nexus 5x). The mobile testing was on the newest release of Firefox available and it worked well. Older browser versions may have variable results, as will other browsers (Chromium, Brave, et al).
Source Code
While I do not participate in collaborative development (I do not take pull requests or solve issues for folks, but if you'd like to hire me for a living wage to do so: get in touch), this is a Free Software project. You are welcome to download the Peregrin source code and modify it as you wish, including making and hosting your own version.
I hope you enjoy some great books!