Add Rounding Value module before Total

[ruslyrossi]

Hi,

 

i'm using prestashop 1.6.1.1 and this version is great. But i would like to add new feature "Rounding Value" like below image.

 

 

 

In other e-commerce platform example Opencart you can create any module and set the sort order before Total. 

 

I know in Prestashop we can use Round Mode (http://goo.gl/dkULCE) but the reason i want the add Rounding Value is because i want to display how much we do rounding.

 

Thanks,

Rusly