Multiple Screen Sizes in AndroidAuthor: Tomas Forde
One of the big differences we found between iOS and Android development, is handling the multitude of screen sizes that come with Android devices.
The Android solution to this has changed in Android 3.2. Prior to this, different screen layouts could be specified for small (~<4 inch), normal (~4 inch), large(~6 inch) and xlarge (~10 inch) screens. In Android 3.2, you can specify layouts based on dp (density-independent pixel) units.
What we like most is that layouts can be specified for different available screen widths, meaning that layouts can be specified for different screen orientations. The YouTube app on the GalaxyTab does this very well; in the portrait orientation, the related videos section appears at the bottom, but when switched to the landscape orientation, this section appears on the right, making maximum use of the space available.
The android documentation contains detailed information on screen support, including how to handle screens of differing pixel densities.