In the new world of touch, swipe should replace click as the primary user input method.
One of the biggest issues I have with Gmail iOS app is the typical '2- click process' to delete/archive mails. With the new Mailbox app, I can handle mails much faster due to swipe based input.
A lot of apps translate PC UI, optimized for qwerty keyboard, to smartphones / tablets - which results in poor interface.
All app developers should optimize their user input on swipe and shake.