In case you just upgraded your iOS powered device to iO7 or any other version and now this device runs slower than it used to, this resetting of the device procedure might speed things up.
If you are using Facebook social apps for watching videos, reading content and you don't want your friends or everyone to know about your activity, you can turn this off.
If there is a vast number of unimportant unread emails accumulating your Gmail inbox and it's starting to bother you, but you don't have time or nerves to mark them as read page by page, this is what you can do.
