Graziana and Rocco's huge free library of grammar, idioms and usage videos.
About this tool →Details
Probably the broadest free Italian grammar archive on YouTube, with matching written lessons and exercises on the site — strong on the fiddly stuff (prepositions, pronomi combinati, false friends, regional usage). Videos are in Italian with subtitles, so they work from about A2 upward. Free to browse; lessons with their teachers and premium courses are paid. Presentation is fast-paced and ad-heavy, which not everyone enjoys.