I have not fooled around or played with this app, so I don't know if it is worth anything, but I thought I'd leave a note here.
Dyscalculator | SHAPE ApS. — apps in perfect shape.
5% of the world’s population suffer from dyscalculia. Dyscalculator is a tool we developed to help those people so they can get better at math and understand numbers. The app features standard calculator operations, but also has a wide range of tools to help people with math disability.