Delete duplicates

If you are sure that every duplicated category is storing exactly the same number of items in both categories, you can delete every duplicated category except one (keep the one with the small cloud icon in front of the category).

Otherwise, I advise you to follow those steps to make sure you won't delete some important information:
First, I would like you to export backups on the Cloud or iTunes, to make sure you won't lose data.

Second, to delete the duplicates, I would like you to :
- merge the duplicated categories,
- then enter the "all" category,
- sort the items by alphabetical order,
- then delete manually each duplicated item to make sure you won't lose data.

Follow the steps to merge duplicated (also called "like") categories :
- enter the category,
- then click the selection item (second on the right, at the top of the screen)
- select every item in the category,
- Click on the folder icon (second on the right, at the bottom of the screen)
- Click on "move"
- choose which category you would like to move the items in (a like category)
- repeat this operation as many times as you have like categories.

Once it's done, export a backup.