Missing features

This app can graph functions I found, but the whole reason I bought it was for some of the things a TI can do that the iPhone calculator cant. Namely, I wanted a function to included the previous answer from an equation and to have arrows to easily move the cursor around where the equations are being typed to change values. Neither of these basic functions are included in this app however.

El Shane about RK-83: Scientific Graphing Calculator, v1.2.3