WebShopApps
Matrixrate
webshopapps/module-matrixrateCalculates shipping rates based on destination, weight, price, or quantity using a CSV file. Allows defining custom shipping methods and rules.
ShipperHQ ProductRate
webshopapps/module-productrateAdds per-product shipping fees set on each product and totaled at checkout, with optional flat or percentage quantity surcharges, configured directly on the product without CSVs.