This extension will automatically hide the findbar whenever you change tab, and by doing that freeing valuable vertical screen real estate.
The reason why this is useful is evident! When ever you use the findbar to search for content on a web page the findbar will stay open until you close it explicitly. So even if you change tab the findbar will be present at the bottom of the Firefox window, even though you most likely won't need it. And if you do need it, you'll probably press Ctrl+f anyways and the findbar will be focused.
Source code and bug tracking at bitbucket
The reason why this is useful is evident! When ever you use the findbar to search for content on a web page the findbar will stay open until you close it explicitly. So even if you change tab the findbar will be present at the bottom of the Firefox window, even though you most likely won't need it. And if you do need it, you'll probably press Ctrl+f anyways and the findbar will be focused.
Source code and bug tracking at bitbucket