While it is functionally limited, I can see it being useful for kids.
"The app Myscript Calculator allows you to enter calculations on a touchscreen by writing them with your finger or a pen. The handwriting is recognized and instantly transformed to a formula and a result.
See the tutorials for all the clever options, and see the smile on your face when playing with it.
What really struck me was the effect on one of my children who has trouble with math.
Visually constructing calculations together, showing what parentheses do, how you build up from simple elements to more complex equations, see what errors do and how to correct them: all of a sudden it makes sense to her.
One of THE most striking examples how teaching can be lifted out of the stone age..."