When a product is ordered through the teelaunch app, our shipping cost are included with what you will be charged. We charge a flat fee on all your products shipped.
Example: Cost of a mug is 3.50 and US shipping is 4.50 you will be charged 8.00 for this order.
When setting up your shipping it is done though the Shopify back end. On the left hand side go to SETTINGS - SHIPPING - ZONES AND RATES. When setting your rates think about the Domestic and International Rates.
If your store has many products from different venders you might want to think about a 3rd party app to give you better control over your shipping needs.
If you have any other questions or concerns please feel free to visit Shopify customer service and search shipping.