FYI, double-tapping the Home button shows you a list of recent applications. That would be the most commonly used way of switching apps, and it's one of the fi

FYI, double-tapping the Home button shows you a list of recent applications. That would be the most commonly used way of switching apps, and it's one of the first tips that is shown to a user on a "new" phone by the OS. Four finger swiping is an optional feature that power users can turn on. Discoverability is still a valid issue, of course.