Here's graphDS v0.4. I added a feature that lets you adjust the graphing window and the starts, stops, and increments for parametric and polar graphing. I also fixed the function input so that you can enter functions that are as long as you please. On the graphscreen's keyboard, I added a delete key, e, pi, and y (note: the y variable can only be used for slopefields and Euler's method, which currently cannot be accessed in the program).