Opens websites on sidebar by addon button popup. - Add sites and open through button panel - Site list does not shared with bookmark, but shared via firefox sync (not tested - seems to be not working) --- instead of using this addon, you can just use function of bookmark, called "Load this bookmark in the sidebar". (I didn't know that sadly, but This addon could be more convenient than native functionality in some case.) --- bug report and other else: https://github.com/sftblw/Webpage-Sidebar/issues
