When designing screens for mobile devices, keep the following in mind:
- For touch screen devices, verify that the application displays correctly in both landscape and portrait views.
- Develop the user interface so it is consistent with existing applications for the specific platform so you can leverage users' existing knowledge for how to navigate applications on that particular platform. For example, let users open context menus in applications by clicking the trackball or trackpad for BlackBerry applications.
- For BlackBerry and Windows Mobile devices, put all actions a user can perform in the full menu for the application.
- Design the user interface so users can access information quickly and display only the information that is immediately relevant to the task.
- Limit the number of controls you place on each screen.
- Organize controls or groups of controls by using line separators.
- Display the most important information at the top of the screen.
- Include a navigation bar that describes the contents of the screen.
- Think about localization requirements early in the design process as localization can affect the layout of screens.
- Prompt users with a dialog box to save any unsaved data before closing a screen.
- Allow users to easily backtrack and undo actions in case they make a mistake.