The present invention provides inter alias electroplating compositions, methods for use of the compositions and products formed by the compositions. Electroplating compositions of the invention are characterized in significant part by a grain refiner/stabilizer additive comprising one or more non-aromatic compounds having null electrons that can be delocalized, e.g., an null,null unsaturated system or other conjugated system that contains a proximate electron-withdrawing group. Compositions of the invention provide enhanced grain refinement and increased stability in metal plating solutions, particularly in tin and tin alloy plating formulations.