Design an App Mockup

Hello I need a developer to develop a Fee Calculator for exchanger website I need it to be like the one in the websites that I am adding here [login to view URL] and this one [login to view URL] The idea is to have a drop down for buy, sell and exchange as you can see and I can create as many converts as I want from-to And I will place it in a buy page for buy, sell page for sell and exchange page for exchange, bear in mind that there will be fee calculator for percentage and fees as it is shown in the url [login to view URL] So in general I will need the one like the fee calculator that is in this site [login to view URL] or similar. So what are your ideas? Thanks William