Developing for Multiple Screen Sizes in Android
One of the challenges that you will encounter during your time as an Android developer is developing apps for multiple screen sizes. There are many things to keep in mind during your adventure into screen sizes. The list below should help keep you on track.
The size requirements for each icon in each density vary for each type of icon. You find launcher icons, menu icons, status bar icons, tab icons, and many more. They are all built differently for each screen density. When building these icons, reference the Android Icon Design Guidelines.
Try to always use the density-independent pixel (dip) measurement unit when defining your user interface. This helps your application scale to different devices. The density-independent pixel is a virtual pixel that scales proportionally for each given screen density.
Provide the supports-screens element to the AndroidManifest.xml file to help the Android market determine whether your application is compatible with various screen sizes.
Provide graphics for high-, medium-, and low-density devices. Although this may increase your development and design time, it will greatly improve the usability and appearance of your application.