GraphDS is a program for the DS that implements the class and performs calculations.
Release notes:
I’ve made some more progress on graphDS. Now there’s an easier-to-use keyboard and it can even graph equations. Riemann sums and integration have their own keys, but the syntax is still the same as before.
Integrate: int(expression, left limit, right limit)
Middle Riemann Sum: RM(expression, left limit, right limit, rectangles)
Left Riemann Sum: RL(expression, left limit, right limit, rectangles)
Right Riemann Sum: RR(expression, left limit, right limit, rectangles)
http://palib.info/forum/modules/newbb/viewtopic.php?viewmode=flat&type=&topic_id=4316&forum=9