Here's graphDS v0.7. I added tracing for Cartesian, parametric, and polar equations. You can use the D-Pad to scroll along the function and the bottom screen will display values for the independent and dependent variables. Or, if you prefer, you can enter a value for the independent variable and the cursor will jump to that point on the function. I also tweaked polar graphing so that it graphs 2x faster than before.
Edit: Download (free... see later post): graphDS v0.7
You can find more info at my site. If you like graphDS and want to help me pay for college, you can make a donation.