Chaka Book Reader app
Chaka is an Android app based on MuPDF Android PDF Viewer. It doesn't care about books management. but dedicates to book reading experience, with most expected features:Horizontal / Vertical Flipping.
Right-to-Left Forward reading mode, for some reverse reading direction books.
Single Column mode, to work with Scanned Dual-Spread PDF documents.
Cropping Margin, to get more visible reading area.
Focus mode.