Shopify store: Multi-currencies auto change based on IP

This is to complete an unfinished project started by another programmer. Here is the unfinished project page https://www.freelancer.com/projects/CSS/Shopify-store-Multi-currencies-change/#/details He did add different currencies dropdown menu to my Shopify website but couldn't update the website based on their geo-location. I am looking for someone to finish this ... --To update website's currency based on user's IP address/auto detection by their geo location. ***Please only bid if you know how to do this. **** Budget is $20.