Remove test variables and leave only "x" variable
Add navigation controller and link root to calculator view
Add in course supplied Axes Drawer class
Add graph button
Add stub Graph View controller with segue
Add GraphView with axes
Add graphView to GraphViewController outlet.
Implement GraphViewController and GraphProtocol
Add segue to GraphViewController
Remove space in Calculator Brain
Implement drawRect to draw graph from equation
Add struts and springs to handle landscape view better.

Also add label for displaying equation
Fix scaling of graph. Remove hardcoded origin value and use property
Link equation label to outlet and set value on view load
Add pinch gesture to view controller
Add pan gesture and fix origin bug in drawRec
Add double tap to move origin
Add save graph scale and origin
Only use user defaults when defaults are set. Otherwise use view defaults
Add iPad storyboard