Hello,
The browser scrolling feature uses "auto-scroll" to scroll the page.
This addon in the default settings emulates "scrollbar dragging" (it's same as clicking the scrollbar and dragging it up-down).
But what's more, there is a lot of settings in the Options page that can further improve or change scrolling (like the Momentum).
I should probably make a new video that demonstrates these features :).
Have a nice week :)
Best Regards,
Juraj Mäsiar

Hello,
It depends on the point of view :), I can see the source code just fine.
Seriously now, I've spend countless hours implementing this addon (and many other addons) and it's completely free.
Is that not enough?
Imagine if you did something free for others and people would still complain. It's discouraging.
Note that Mozilla reviewers can also see the original source code (for all of my addons) so they are safe to use.
Best Regards,
Juraj Mäsiar

Hello,
See the Options page to set a scroll button you want to use.
Also, the addons won't work here - on the mozilla addons page, so try it on any other page.
Best Regards,
Juraj Mäsiar