If a tab is hidden from your user profile, you will not see the tab, even if it is included in a custom app/console that you are viewing.
Tab visibility is determined by the following:
1. The tab is included in the custom app/console that is displayed in the AppExchange menu.
2. Tab visibility is default on or default off (not hidden) in your user profile.
3. You have not customized your personal display settings to remove the tab from the list of included tabs. This usually happens when the administrator customizes the app properties and checks the "Overwrite users' personal custom app customization checkbox" - this reverts to the desired tab display of the administrator.
For more information see:
Customizing Your Tabs