Good extension but the development seems to have stopped. I've made a fork "Page up and down buttons for e-ink" of it.

works perfectly! if you have an e-ink display this add-on is a must. unfortunately, firefox makes it very difficult to install non-recommended add-ons. to install this add-on you will need firefox nightly and allow for the option to add custom collections.

so great! I just want a scroller can easy pagedown and page up with no feeling, the plugin completel it.