If you're developing a userCP only application, you might find yourself in a place where you want to hide the tab for some groups.
I've suggested that IPS add something to the main application that allows us to add raw PHP code, which is executed when forming the ipsRegistry::$applications array, were we could fetch our values for a different setting, and show/hide the application tab according to that. Until them, this will work.
In the method "getLinks" in your applications usercpForms.php you can add something like this to the very beginning: