Android scroll bottom от DaveRo

On Android, click the 3-dots to get the menu.
Tap 'Add-ons'
Tap 'Scroll to bottom' to scroll the current tab to the bottom of the page.

On desktop it adds a green down-arrow icon to the toolbar.

There is a companion add-on - Android scroll top

On a responsive site, one which fetches more content automatically when you read to the bottom, it will scroll to the bottom of what's currently downloaded.