graphDS is a program for the Nintendo DS that can evaluate mathematical expressions and graph Cartesian, parametric, and polar equations.

Release notes:

In v0.9.1, I focused on fixing bugs with graphing. Graphing will no longer result in random pixels and lines being plotted and I’ve also refined my algorithms so that weird things don’t happen near the edges of the screen. Please be aware that I also resized the graphscreen, so there will be a white space 4 pixels wide around the entire graphing area.

http://forum.palib.info/index.php?topic=6583.0