TachiyomiJ2K - Manga Reader

Features of Tachiyomi include:

Online reading from a variety of sources
Local reading of downloaded content
A configurable reader with multiple viewers, reading directions and other settings.
MyAnimeList, AniList, Kitsu, Shikimori, and Manga Updates support
Categories to organize your library
Automatic light and dark themes
Schedule updating your library for new chapters
Create backups locally to read offline or to your desired cloud service

Plus some new features in this fork such as:

New Manga details screens, themed by their manga covers
Combine 2 pages while reading into a single one for a better tablet experience
An expanded toolbar for easier one handed use (with the option to reduce the size back down)
Floating searchbar to easily start a search in your library or while browsing
Library redesigned as a single list view: See categories listed in a vertical view, that can be collasped or expanded with a tap
Staggered Library grid
Drag & Drop Sorting in Library
Dynamic Categories: Group your library automatically by the tags, tracking status, source, and more
New Recents page: Providing quick access to newly added manga, new chapters, and to continue where you left on in a series
Stats Page
New Themes
Dynamic Shortcuts: open the latest chapter of what you were last reading right from your homescreen
New material snackbar: Removing manga now auto deletes chapters and has an undo button in case you change your mind
Batch Auto-Source Migration (taken from TachiyomiEH)
Share sheets upgrade for Android 10
View all chapters right in the reader
A lot more Material Design You additions
Android 12 features such as automatic extension and app updates