Kotardo is a free and open-source manga reader for Android with built-in online content sources.

Main Features
Search manga by name, genres and more filters
Favorites organized by user-defined categories
Reading history, bookmarks and incognito mode support
Download manga and read it offline. Third-party CBZ archives are also supported
Clean and convenient Material You UI, optimized for phones, tablets and desktop
Standard and Webtoon-optimized customizable reader, gesture support on reading in