Mobile usability has improved over the past 7 years due to better prioritization of content over UI elements and better understanding of the users’ needs.| Nielsen Norman Group
iPad apps are much improved, but new usability problems have emerged, such as swipe ambiguity and navigation overload.| Nielsen Norman Group
Interactive elements must be at least 1cm × 1cm (0.4in × 0.4in) to support adequate selection time and prevent fat-finger errors.| Nielsen Norman Group