From the ShipRush Team Room...
It is true! ShipRush now integrates with Opencart.
ShipRush FedEx is of course %100 free of charge. Get it here: http://fedex.shiprush.com/opencart/index.shtml
ShipRush USPS without postage is also free of charge. http://shiprush.com/usps
ShipRush for Stamps.com, with full postage printing, is $29.95/month after the first month. Get it here: http://stamps.shiprush.com/opencart/...rt_index.shtml