The site for it is tradeexpert.net. It is a script for trading traffic between adult sites and it has a free plan but it will take some percentage of your visitors so they skim your traffic as you can see on their sale page.
Most of the trade scripts are the thing of the past since they are outdated and most of them have not been updated for many years and they obviously have many security loopholes.
I have heard about Trade Pulse as well. You can try both of them (TradePulse from scriptpulse.com and TradeExpert) and for free for a few days and see if they are worth paying for.