The Google Play Store is a publishing platform that helps you publicize, sell, and distribute your Android applications to users around the world.
To register as a Google Play Developer and get started with publishing, visit the Google Play Android Developer Console publisher site. You can sign up for an account at https://play.google.com/apps/publish/.
A launcher icon is a graphic that represents your application. Launcher icons are used by applications and appear on the user's home screen. They can also be used to represent shortcuts in your application. These are similar to the icons created for iOS applications. The following are the launcher icon requirements, which also need to be in a 32-bit .png format:
Icon-ldpi.png: This is a 36 x 36 px image at 120 dpi, which is used for low-density screenIcon-mdpi.png: This is a 48 x 48 px image at 160 dpi, which is used for medium-density screenIcon-hdpi.png: This is a 72 x 72 px image at 240 dpi, which is used for high-density screenIcon-xhdpi.png: This is a 96 x 96 px image at 320 dpi, which is used for x-high-density screenIcon-xxhdpi.png: This is a 144 x 144 px image at 480 dpi, which is used for xx-high-density screenIcon-xxxhdpi.png: This is a 192 x 192 px image at 640 dpi, which is used for xxx-high-density screen.Launcher icons need to be placed in your project folder at the time you build your application. The Google Play Store also requires you to have a 512 x 512 px version of your icon, which can be uploaded in the developer console at the upload time of your build. For more information on launcher icons, visit http://developer.android.com/guide/practices/ui_guidelines/icon_design_launcher.html.