This app is loads of fun to test how fast I can do random equations. I can even choose weather that is addition, subtraction, multiplication, or division. However, I can't choose to test my multiples of 7, or divisions of 8 - both of which I'm significantly slower with than other equations. This app would benefit from being able to test specific numbers, like ordered flash cards. Also, it would be cool if I could choose a user's slowest equations and only do those - so I can get better at them. Maybe both of those could be fixed by being able to make custom tests.
Otherwise, a great app, minus the expensive price.