misleading Rated 1 out of 5 stars
this addon clears your sessions, it does not manage them.This review is for a previous version of the add-on (1.0.1-signed.1-signed).
You seem not to have understood the description, screenshots, etc. (it might be partly my fault for not making it clear enough). The current version makes use of the obscure back/forward button context menu; in other words, you have to right-click on one of those buttons to access it. The "Clear session history tree" function was provided just in case the tree gets corrupted, and does not clear session history itself.
Also, a new version is in the works that provides a more user-friendly interface, in the form of a sidebar. If you'd like to take a look, see the "Development Channel" section at the bottom of this add-on's description page. You can then access the sidebar under View > Tools, or set up a keyboard shortcut in the add-on options.