4th Grade Math - Math Galaxy

I purchased this app for my son to learn 4th grade math but it gives a blank screen after open the app

We started using this app when my son was in the 4th grade and had some difficulties with math. To our surprise in a few weeks he became much better. We still like playing this app and will definitely download next grade version. However I wish the graphics and interface were nicer.

That's a very useful app and definitely costs its money. For me and my kid ist's more interesting to solve problems in math using iPad and have fun together. All the tasks are very good and the app is made good too.