Facebook - SnapChat

I have explored my privacy settings on Facebook.  I already have my posts and pictures set so only people that I am friends with on Facebook can see them.  I also use the timeline review setting so I can approve or not approve things people want to add on my timeline.  Sometimes I forget to check so I might have several posts that people wanted to add.  Regarding SnapChat I have four kids and was made aware of the fact that this app discloses to any of their friends their exact location and movements.  I have discussed with them the dangers of this and have asked them to keep their accounts in Ghost Mode for their own protection.