Do you want to install the app or run the app, in the background? Assuming that you want to install the app in the background, then you have to go to the Google Play store and search for the app, then click to install the app, then the app will install and automatically, show the download icon on the top of mobile phone, in the background. You can do anything while the app is installing by its own. If the app is install, then it is ready to use.
Assuming that you want to run the app in the background then you should start an app like music player, and play games while music app run in background.
I hope both the answers of mine suffices your query.
HOD (CSE), AKSU, Satna
Life is full of surprises and compromises!