Design the user interface (UI) so that the user can navigate and interact with the application easily and efficiently. You can improve usability by providing the user with:
Easy access to application options
Shortcuts to frequently used information and input data
Fast ways to return to previous states or views
Minimum number of required inputs
Customized input methods that direct the user to input the right kind of data
Unless your target devices all use the same input method, design the UI to support both key input and touch input. If the application is run on a key-based device, the UI responds to key input. If the application is run on a touch device, the UI enables touch controls. For instructions on how to implement key and touch input in your application, see section Handling user input. Customize the UI elements for the different input methods where necessary.
When designing user interaction for your application, also consider the following issues:
Text fields—Consider whether to use default text input methods provided by the device or custom input methods optimized for your application.
Feedback—Provide feedback that guides the user through problem situations and helps keep touch interaction responsive.
Focus and visual guidance—Provide visual focus and other guidance to help the user navigate and use your application efficiently.