Are you looking for a program to use with your students or maybe your own children? I suggest that you look into K5 Learning. This web-based program is interactive and targets your students level once they have taken an assessment. The assessment will give you targeted results and you can dig deeper into the results on the website.
My students have used the program for a couple of weeks now and seem to enjoy it. I like the graphics, lessons and that it specifically targets their needed skills. I look forward to seeing their results as they continue to use the program.
The one thing I need to point out about this program is that it is web-based and works on computers. I hope that they develop an app to use in the future.