With the growing popularity of Smartphone market, the development of mobile technology has gradually been changing the interpersonal communication, from the past telephoning or SMS towards a more personalized, instant and interactive user scenario. Both the traditional PC application and innovative mobile one launch the mobile versions to the big market to fulfill various user requirements. However, different from the traditional PC interface or the larger size of tablets, many mobile application developers will make usability considerations and trade-offs on the arrangement of user interface and functionality in order to apply the interface design on a small handheld touch screen, but those indirectly have spawned a lot of usability problems.
