Closing out of all the applications in your App Switcher is generally frowned upon because it defeats the whole purpose of having apps suspended for faster loading times the next time you go to use them. On the other hand, some people just can’t help themselves.
If you fall under this category and you wish there was an easier way to close out of all your App Switcher’s apps in one fell swoop, then you just might take a liking to a jailbreak tweak release called KillBackgroundXS by iOS developer ichitaso.