I need a tabbed application with core data persistence. when i create a new project with Tabbed Application template, i can not find the "Use Core Data" check box. Is it okey to manually add a core data to a project created with Tabbed Application template?
It's not there because there is no standard way to implement core data view controllers in an tabbed application like there is in a table based app.
Yes it is okay to add Core Data to every project you create. You can use a core-data enabled template for reference.
Yes, you can add it yourself. Or you can the empty template and add the tab bar controller yourself.
来源：https://stackoverflow.com/questions/9902596/why-there-is-no-use-core-data-check-box-with-tabbed-application-template