Calculator: $5 Address book: $3 Notepad: $2 Camera: $40 ... How is creating a useful application for an expensive device that replaces an inferior took an exam

Calculator: $5 Address book: $3 Notepad: $2 Camera: $40 ... How is creating a useful application for an expensive device that replaces an inferior took an example of excess? It's not really like people buy iPads simply to replace a pack of notecards and nothing else.