Categories are a useful way to sort your items, especially if you have a lot of them.
The categories screen gives you a list of your categories as well as an overview of what items are inside it.
You can resort the categories by long-pressing and dragging (on Android) or by using the edit button (on iOS).
Press the (+) button to create a new category. Enter a name and then use the Edit Items in Category to add and remove items from this category.
The Edit Items in Category screen will list all of your items alphabetically with the items already in this category at the top. Simply tick any items you'd like to include in the category and they will move up to the top of the screen. Untick an item to remove it from the category.
You can also create new items directly into a category using the Create New Item button.
Simply tap a category to edit it as above.
You can also use the Delete Category button on the Edit Category screen to delete the category completely.
When categories are enabled any items that aren't in any category will appear at the top level of the register under Uncategorised.