What's FirefoxOS plotting calculator?

Aim
This application is part of Mozilla Student Project from Université-d'Evry-Val-d'Essonne.
This project enables to print graph of Mathematic functions.

How does it work ?
1/ The application user enters the function defintion parameters.
2/ The user click on the button "print the graph".
3/ The graph is printed.
4/ The button back on the top-left enbales to repeat the process for another function.