when you go to settings page, scroll to the bottom left, it lists apps. Why does it only show some apps? And In my case it only show 3 apps, but I have many loaded. How do you have all the apps show in the list?
The developer of the app chooses to put their app into the settings pane IF the app has settings they think should be set there.
Some do, but many don't. It's nothing to worry about.