The current System UI implementation now exposes the problem that widgets on the home screen seem to be "hard-wired" as their top windows remain being displayed even if an app has been stopped. In an earlier version, an app was restarted if its widget is shown on the home screen. This is not good either. This is what we should get instead:

• dismiss a widget if an app has stopped
• if the design requires at least one widget to be shown then
  • try to restart that app once, but if it fails stop trying to avoid a dead loop
  • Its widget shall show a message, something like "content is not available"
• The latter requires a kind of "bad app" to demonstrate this capability to the user