Its main function is as a calculator, but the keyboard can be used for many different uses.

The Mathematical Keyboard comes with Mathstrudler. The two apps can easily be integrated.

Mathstrudler - SwissArmy-Type maths keyboard

Mathstrudler is a Swiss-Type-style keyboard for Math. It offers a very handy way to perform calculations, create tables, employ unit conversion and much more.

Actually, the Mathstrudler App 50e0806aeb ragodea