In ShipStation, it's easy to search for orders that are associated with a barcode, be it from the web app or the ShipStation Mobile App. There are two ways to bring up the Scan Search popup window below. The easiest is to press Ctrl + Shift + S (or Cmd + Shift + S on a Mac) within the Orders screen.
You can also access the Barcode Scanning Search by going to the Other Actions dropdown, and selecting "Scan Barcode."
You can select a status you want to search in, and chose what you want ShipStation to do with the order: display it, ship it, or add it to a batch.
Scan using your iPhone!
Another option for scanning is available to iPhone users. (Android is not yet available) Open the ShipStation Mobile app, and head to the orders tab.
From there, click the vertical ellipsis to view more options, and tap "Scan Barcode". (This is intended to work with an order number barcode, but will also pull up all orders containing a specific item if you scan the SKU's barcode.)
Once the barcode is centered in the screen with the red line, it will automatically scan the barcode.
Once scanned, the order will pull up!