MATH FACT PRACTICEGreg Tang Kakooma puzzles (addition and multiplication)https://gregtangmath.com/kakoomaMULTIPLICATION GAMES
These sites have all kinds of math games, including multiplication:
MATH WORKSHEET CREATOR4th Grade Math Activities (not just fact practice)
IXL - Requires membership. Online games that track student progress as they practice target skills.
Adapted Mind Math Worksheets
Free math worksheets specifically linked to 4th grade standards for extra at home practice
Splash Math (free, but requires login)