Acetone is not strictly polar or non-polar, just more polar then something like a saturated hydrocarbon. For example when it is used in the lab as a solvent for cleaning glassware it is an excelent solvent for grease and such on ground glass joints, then when the grease is cleaned off with acetone water can be used to wash off the acetone, being that acetone is misicible with water and acetone will also dissolve many non-polar compounds.
