Extensions can use the chrome.windows api to view currently opened app windows and monitor when app windows are opened, closed, and focused. Extensions can use chrome.windows.update to set app window properties including dimensions, position, and focus.

Extensions can also open apps using chrome.management.launchApp and close all of an apps windows by disabling and then reenabling the app using chrome.management.setEnabled.

Extensions should be able to selectively close app windows and close them without disabling the app. This can be achieved by extending the chrome.windows.remove api, which currently throws a no window with id error when called for app windows.