How do I add/subtract item stock by scanning barcode?

You can easily increment or decrement item stock simply by scanning the product barcode. Additionally, if you do not yet have the item in stock location you can easily add it by scanning the barcode. To begin scanning, tap on the barcode icon above the big circular + button on the bottom right of the Stock screen as shown below. This will bring up a popup menu, select whether you want to increment or decrement an item stock. (If the item does not yet exist, then just tap on "Scan to add item stock".)