To use our Rates features you will need access to Shopify's Carrier Service API. It's free with annual plans or $20 on monthly plans. Contact Shopify to add Carrier Service API for you.
We offer a 14-day free trial so that you can check if the app suits your workflow and does what you need.
The app works everywhere that Shopify does.
Charging a minimal transaction fee allows us to accommodate businesses of all sizes from small startups to multinationals.