Here are some great apps to help reinforce what we work on in lessons. They are inexpensive (some are even free) and really great music learning tools for kids. I've seen great success in kids who choose to use these fun apps!
Rhythm Cat (lite version is free; full version is $2.99)
This app features various levels where students have to tap out the rhythm shown on the screen. The graphics are great (with cartoon cats in the background) and the app features great rhythm tracks for the student to tap the rhythms along with.