All-in-One Sidebar (AiOS) is a sidebar control, inspired by Opera . Click on the left edge of your browser window to open the sidebar and get easy access to all your panels.Discontinued
The All-in-One Sidebar is not compatible with Firefox 57 and later. The development of this extension has been discontinued. The extension still works on XUL-based Firefox forks like Waterfox and Pale Moon
Slim vertical button to toggle Firefox's (57+) sidebar on/off, on the left of browser. Firefox has native sidebar but no native switch to be touched on the edge of browser. This userChrome script provides experience like All-in-One Sidebar.
This add-on for Firefox provides a few options to make the sidebar more accessible and customize it.Discontinued
The add-on will not receive any more updates and will stop working by next November with Firefox 57, when XUL-based add-ons will be deprecated in favor of the WebExtensions API. See http://fasezero.com/ The extension still works on XUL-based Firefox forks like Waterfox and Pale Moon