Vimium Cheatsheet

h       scroll left
j       scroll down
k       scroll up
l       scroll right
gg      scroll to top of the page
G       scroll to bottom of the page
f       activate link hints mode to open in current tab
F       activate link hints mode to open in new tab
r       reload
gf      view source
zi      zoom in
zo      zoom out
/       enter find mode -- esc to cancel
n       cycle forward to the next find match
N       cycle backward to the previous find match
i       enter insert mode -- esc to exit
yy      copy the current url to the clipboard
ba      go back in history
fw      go forward in history
J       go one tab left
K       go one tab right
t       create tab
d       close current tab
u       restore closed tab (unwind the 'd' command)

what's b?

nvm,
b - Open Bookmark
B - Open Bookmark in New Tab

also,
x - Close Tab
X - Undo Close Tab