Postie

Postie provides your customers with real-time shipping costs from your preferred provider.

Features

Provide live shipping rates during checkout from a number of providers.
Product dimension helper - shows you what products and variants are missing width/height/length/wight details.
Use the CP settings, or a configuration file.
Add markup rates as an extra cost, either as a flat value or a percentage. Great as a buffer for packing.
Provides events to write your own providers and support.