By far the best random social surfing toolbar on firefox. To all those, facing problems with the new stumblebar (stumbleupon floating bar for firefox 57+), please uninstall new firefox 57+. Search for any firefox 56 or below version (works perfectly well, no lag, no hang, using firefox 56 since long time without updating) and install this stumble upon full toolbar. Login is easy, surfing is easy, search is easy, connecting with people of your choice, profession is easy.
StumbleUpon team, if you are getting this, please update this toolbar... it's quite efficient and purposeful.