pathway27 has released bookr-mod-vita version 0.3.0 for the PSVita.

Added ability to zoom and rotate
Re-open file after waking from sleep due to #9 and #13
Using latest MuPDF (v1.13.0)
Added select menu (Press select when reading) for other functions
- Bookmarks
- Book Traversal
- Fit to Width/Height
- Rotation

Download bookr-mod-vita from the Brewology PSVita Store.