How do I install Windows 8 app updates?
All app updates are installed though the Windows app store app. Currently there is no way to have the updates install automatically. As a user you must explicitly initiate the process. Number of pending updates is displayed in the lower right corner of the app store tile and in the upper right corner of the app store app. Clicking on the link in the upper right corner of the store app will show the apps that need updates. Once there you need to click on the install button. Screenshot collection below illustrates this better.