ScrollAnywhereby Juraj Mäsiar

Scroll Anywhere enables you to drag scrollbar with your middle (or right / left) mouse button without actually touching a scrollbar. Just hold the middle button and move mouse up-down or left-right. You can also change the behavior to simple "grab and drag" style.
Now with The Momentum feature (including infinite scrolling) and option to change the cursor while scrolling!
Watch a short preview video here (0:12) or visit www.fastaddons.com / Facebook / Twitter
Warning: very addictive! :)

Known issues:

• does not work HERE on https://addons.mozilla.org/ (blocked by Firefox) BUT! it can be enabled by creating new key "privacy.resistFingerprinting.block_mozAddonManager" in "about:config" page with boolean TRUE value, and in the key "extensions.webextensions.restrictedDomains" remove domain "addons.mozilla.org"
• does not work on browser specific pages like "about:addons" (blocked by Firefox)
• does not work in "PDF view" - broken by Firefox 60
• does not work in "reader view" (blocked by Firefox), vote for bug
• does not work on other extensions pages like options page of some addon (blocked by Firefox)
• may not work in nested IFRAME html elements (may be Firefox limitation)
• infinite Height increase bug in Options page in about:addons page happens when you use + Zoom, see this bug

The Momentum:

• overall performance highly depends on complexity of a web-page / your PC speed / Firefox speed (it should get better with every new Firefox version)
• Momentum is now enabled by default - but you can disable it in Options page - on Momentum tab

Performance tips:

• ScrollAnywhere has one performance option called "Don't lock i-frames when scrolling". You can try to enable this if you experience noticeable delay between pressing scroll button and starting scrolling. However you will no longer be able to scroll through "i-frames" (like some ads or embedded pages).

Be aware:

• left mouse button support is experimental feature - please report any issues to my support e-mail.
• Linux users may want to enable "Don't block default button action" option in Options/Advanced - to enable 'Paste' with middle button again.
• in some Linux versions you may need to disable "middlemouse.contentLoadURL" in "about:config" to avoid navigating to URL from clipboard when pressing middle mouse button

Recently added features:

• Version 6.0
• added auto-fix of context menu bug in Firefox 59+ for Linux users
• Version 5.9
• fixed context menu over YouTube videos
• fixed left click on Select elements
• fixed wrong scroll ratio when applying zoom
• Version 5.8
• added option to disable add-on from toolbar icon menu
• added option to setup keys to Disable / Enable add-on while holding
• fixed broken scrolling on some specific pages
• Version 5.7
• fixed scrolling issues on some specific pages like bugzilla.mozilla.org
• multiplier is now available also for normal scrolling, not just grab and drag
• multiplier can be now set below 1 to slow down scrolling (like 0.5)
• added translations support with Slovak translation
• improved Options page and pop-up
• fixed compatibility with Android (probably)
• Version 5.6
• brand new Options page - with navigation tabs on left side
• icon for toolbar for easier access to Options page
• option to change cursor while scrolling!
• improved "links locking" when using middle mouse button and scrolling starts over link
• Momentum for everyone - momentum is now default

Note:
I'm developing this add-on in my free time for you for free. Please consider supporting my work by becoming my Patron or by donation. Thank you :)