You’ve got an idea for a mobile app. What do you do?
As a programmer, I find myself wanting to jump right into Xcode to prototype but I have learned the hard way to mock it up first. Whether the app is mine or belongs to a client, I sketch the user interface. Inevitably, a few iterations happen immediately just by visualizing how the pieces of the app will interact. If the work is for a client, go over it with them. If not, find a friend who is willing to be bound by the FriendDA and walk through it.
My iPad app of choice is App Cooker due to the breadth of its design abilities such as an icon editor, store prep and a method for helping determine the app price. The glaring omission right now is the split view controller but they say it is coming. There are many similar apps such as Blueprint, iMockups, SketchyPad, Interface HD and others. There is also a cross-platform solution in Balsamiq Mockups.