If you use Log in with Facebook on Sites like Spotify, etc then you will no more use this feature. Many Users also added their Twitter and Instagram account their in Facebook. These Users also can't access their Twitter and Instagram through Facebook medium because these applications also work and run through/with Facebook apps and if you disable your Facebook apps then application no more access your account. This Trick only useful for; those uses Facebook for chatting, etc purpose only.
How to Disable Apps?
#1: Log in to Facebook
#2: Click on Settings
#3: Click on Apps Option from left side menu or click here
#4: Click on Edit button for Apps, Websites and Plugins.
#5: A popup will appeared. Then click on Blue Disable Platform Button.
#6: Done
