Unbelievably enough, I couldn't find an answer when Googling for this very basic question!
I noticed that since I upgraded from Eclipse Helios to Eclipse Juno and updated the Android SDK, Eclipse places a file called ic_launcher-web.png in the project root whenever I create a new Android project. The file is the same as the application icon selected in the project creation dialog, but what does it do? As mentioned, it's in the project root, not in any of the /res/ folders. So is it included in the finished .apk file, and what is it's purpose?
There is a little bit of an explanation here on this page:
http://developer.android.com/guide/practices/ui_guidelines/icon_design_launcher.html#size
It's for the Play Store, which accepts 512x512 high-resolution icons:
(A more tutorial like explanation can be found here.)
It is not used in your actual app or the launcher, so it is not packaged in the APK.
If you keep this file make sure to change it to duplicate your regular launcher file. You manually add the regular launcher file to the play site when submitting your project anyway so the extra web launcher file may not be needed. My first project never had one.
This is the icon for the google play store. You need to provide a 512 x 512 icon.