The Royal Mail Shipping Extension app enables you to offer real time shipping prices to your customers during the checkout process.
When a customer goes to complete their purchase, they are offered different shipping services based on products weight and location. They choose the desired service, and the price is added to the total of the order. Simple!
Please note you need a Shopify plan with real-time carrier shipping for this app to work.
This app does NOT print Royal Mail labels, for that please see this app