Items can be added while creating an invoice or estimate, but you also have the option to add them independently for future use. To create an item:

1. Tap on the + (icon) on the Home screen.
2. Select Item. Or, from the Items tab, press the + (icon) in the top-right corner.
3. Simply select a name for the item, specify a price with unit type and discount, and indicate if it is taxable. 
4. Optionally, you can also add a description and an item photo.
5. Tap on Save.