How do I add an item to my 'Regular items' shopping list?

Within the edit popup

1. Navigate to your shopping list
2. Tap on the arrow to the right hand side of the item you'd like to edit, this will expand it down to display all of the item's information
3. Tap on the additional information, this will open up the edit popup
4. Hit the star icon in the top left corner' to add the item to your Regular Items list

Within the Regular Items list

1. Navigate to your shopping lists
2. If you cannot see all of your lists, hit the filter shopping list icon
3. Tap on the 'Regular Items' list
4. Tap on the big circular + button at the bottom of the screen 
5. Tap on the text lines icon
6. Type in any items you'd like to store in this list
7. Hit 'Add items'