Code Squad ($0.99) is a great multiplayer app available to practice math computational facts. The app focuses on the team's success to move from level to level, while keeping track of individual progress.
When you begin playing the game, you are asked what operations to practice; addition, subtraction, multiplication, division, or a combination of the four. The next question is to select the level; easy, medium, or difficult. Then the practice begins. Below is an example of the easy level for mixed multiplication and division.
When complete, the app will reveal how many each agent answered correctly, and if you are successful you will move onto the next level.