InUpdate 3, Microsoft has finally addressed one of its users' key complaints, and you can now very easily shut down any app. This functionality occurs as it does on other mobile platforms, in what Microsoft calls the App Switcher experience.
In the original version of Windows Phone 8, some users would repeatedly tap the Back button in order to remove running apps from the "back stack," and, they hoped, shut them down completely as well. But this action didn't actually shut down any apps. Instead, the Windows Phone OS would automatically manage memory and tombstone and then shutdown apps only when needed.
But with Update 3 installed, you can now use the App Switcher UI to shut down apps for good.
You access App Switcher as you did before: Simply press and hold on the hardware Back button. When you do, each running app appears as a tile in the center of the screen, and you can swipe left or right to navigate between the available apps.
Two things have changed in Update 3. There is a small icon next to each app name, which can help you remember which app is which, since many users visually identify the app with its Start screen tile or Apps view icon. And second, and more important, there is a now a large "X" close button in the top right corner of the middle app. You can tap this button to shut down the app.
When you do, the app tile visually animates and appears to move to the bottom of the screen and then off-screen.
I'll be looking at more new Windows Phone 8 Update 3 features in the days ahead.