Add an extenstion to my Joomla website

I need to add an extension to my joomla website that I had built. Right now we have a tab that says service requests that would allow a customer to post a particular job they need help with in a particular category of there choice amongst the trades industry and then an email would get sent to the requested trades people and then they would be able to contact the customer to quote on the project. At the moment the Service Request tab on my website says coming soon. However, my developer was not able to figure out how to actually integrate something like that into my website. You can visit [login to view URL] for an idea of what I am talking about.