Apvlv is a PDF Viewer based on GTK+2 and poppler which uses Vim like keybindings.
For example, < Ctrl-f > to forward page, < Ctrl-b > to previous page,
'k','j','h','l' to scrolling a page up, down, left or right.
Typing '50' and < Ctrl-f > will go forward 50 pages, typing '30' and < Ctrl-b >
will go previous 30 pages. Apvlv can support view a directory as content of a
pdf document. Pressing 'k' or 'j' to move selected up or down, 'h' or 'l' to
collapse or expand a dir, and press 't' will open the selected document in a new tab.