Graphing Calculator (Gabor Nagy)
Cost as reviewed: FREE
This is a great app for plotting up to 4 graphs at a time. It has all the standard functions and variables you would typically want to graph. It plots the graphs much more quickly than my old TI-83 and it is obviously much prettier (hello! It has color!!).
You can zoom in and out and pan by using familiar iPhone touch commands (pinching, sliding, etc.). In addition, you can double-tap to engage the tracking feature where you can slide your finger along the screen to see the y value results on each line at various x values. The settings tab lets you manually set your min and max x and y values, which is a welcome feature. There is also very good documentation to go along with this great app.
I have two suggestions that might not be too difficult to implement. One would be to have a button on the graph screen that would allow you to automatically recenter on the origin. The other awesome feature would be if it would calculate the intersection points between lines. This is a feature I used quite frequently on my graphing calculator.
I highly recommend this app to anyone who would like to occasionally graph a few lines.
