I am the owner of this script, i got it developed by with my developer. It is made in PHP. People can list their exchange offers. People can talk with exchangers in live chat. Buyer/Seller can also add Escrower in the same chat instantly. It has encryption system as well so you can send your important information among each others.

Here is demo: http://dealsfor.tech/ex

If you are interested. Please message me or drop a reply here. I will give you the cheapest price.