Depending on the pixel densities for the phones , the icon size of the app should be as follows:

Device Type - Icon Size in pixels

   * ldpi - 36px x 36px
   * mdpi - 48px x 48px
   * hdpi - 72px x 72px
   * xhdpi - 96px x 96px

The application icon is present at res/drawable-(dpi)/icon.png. The icon is placed for ldpi, mdpi, hdpi and xhdpi profile in the corresponding directories.