You may already know that Windows 8 apps or modern apps can only be installed from the Microsoft official windows store and does not support minimize, maximize and close buttons. Since there is no close button on the top of the application hence you need to close the running application using Alt +F4 hotkey. Now there is no need to use Alt + F4 hotkey as Stardock has developed ModernMix to add missing features to modern apps.
Stardock ModernMix app comes for 30 days trial. After installing Stardock ModerMix Configuration software you will get missing features to modern apps back. StarDock ModerMix software can be downloaded from the official download link which is provided at the end of the article.
After downloading install the StarDock ModernMix and select the trial. Now minimize the StartDock ModernMix software and from now when you will launch the any Windows 8 store apps you will get minimize, close and maximize button on the top right corner.