You can now simply create, edit or delete a category directly when you're publishing an episodes.

To add a category, enter the category name in the "Add" box and then click the "Add" button. To edit or delete a category, pause your cursor on the category and you'll see the edit and delete icon to edit or delete the category. if you delete a category, you will receive a warning message that any posts under that category will be sent to the default category. 

Choose the category for any post by simply clicking the box before the category name (if nothing is chosen, the post will be filed under the default category).

Please note that the default category can be edited but can not be deleted.