"Rush Shipping extension will add extra feature to normal shipping methode. Extra features are :
1) Admin can set the separate time schedule for shipping and rate.
2) for example : Within 5 days, then it will treat as Rush Shipping and charge for this will be set from admin part in the magento. Admin can change the delivery day limit also.
3) In same way admin can set days slab and price to be charged for that.
"
