Play Store icons and downloaded app icons, same or different I have a quick question regarding app icons. My question is are the icons that are displayed in the play store (the icons you see or click to go to the description of the app before you download) different then the app icons that appear on my home screen after I download and install the app? Or can the two icons, Play Store icon and phone (after download and installation) icon be different? So basically what I'm asking is can the developer use two different icon images, one for Play Store and one as the app image that appears on my phone after I have downloaded and installed the app?
Icons are also provided by your icon theme. But for convenience both kept nearly similar. 
Yes, it is possible to keep two different icons. But, that will create confusion to your user. I can cite you an example of an app. This app is SuperSu. It can change up to 7 icons ( including 1 invisible ) if a user opts.
You can also change app icons by using some app that replaces icon from the app and from your system. For an example see this app.
You can also follow this tutorial to change the icon.