Your applications need a wide variety of icons, from a launcher icon to
icons in menus, dialogs, tabs, the status bar, and lists. The Icon Guidelines
describe each kind of icon in detail, with specifications for the size, color,
shading, and other details for making all your icons fit in the Android system.
The Icon Templates Pack is an archive of Photoshop and Illustrator templates and
filters that make it much simpler to create conforming icons.
A widget displays an application's most important or timely information
at a glance, on a user's Home screen. These design guidelines describe how to
design widgets that fit with others on the Home screen. They include links to
graphics files and templates that will make your designer's life easier.