Mobile devices have small screens and limited processing capacity. Also, users are less likely to use a complicated mobile application, and there is not enough room to explain the user interface on a small screen. So, it is advisable to eliminate complexity and use a simple user interface with only the limited, required functionality that can be accessed easily and efficiently. Keep the screen uncluttered and consider the device types you are designing for. For example, designing for a touch screen is completely different from doing it for a keypad-based device. Selection errors on touch screens are higher than other screens so you may want to surround the touch areas with as much white space as possible.