In the Apps page, what does it mean to make an app "active" & "visible"?
As an account owner, or admin, you'll have access to the Apps page. By visiting your Apps page, you'll be able to mark your apps as "active" and "visible"--this will remove any strike-through marks in the app selector.
The apps marked as "active" will be tracked and you will be charged to track these apps. The apps marked as "inactive" will not be tracked and you will not be charged for these apps.
The apps marked as "visible" will be available in your app selector. The apps marked as "invisible" will not show up in your app selector. If you mark an app as "inactive" and "visible" the app will have the strike-through mark.
For more on how to deactivate an app check out this knowledge base article: