Math Vs. Zombies has received a change of face. I know when I recommended this app in the past for math facts practice, the biggest criticism was that the students were using a gun (laser canon of some sort) to kill zombies.
The change that took place now has the student use magical powers shooting from hands to change the zombies back into humans. So if you had reservations in the past about this application, please take some time to look at it again as they have obviously made some efforts to appease the masses.
via Math Games Math Vs Zombies.