Chaka Book Reader

Chaka is an Android app based on MuPDF Android 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.

---