I was able to get it set up. There is no admin tab. You have to create a Page with the Junxt Template. Then navigate to that page.
There was a Publisher Key hard coded in the template file - I had to replace that with my Publisher key. When I navigated to the page I created I just had to enter my password and it went through the set up process.
Note: the above assumes you created a publisher account at junxter.com and received a Publisher key via email.
I removed the plugin though - I was hoping for a classifieds plugin that I could manage the content on. This fills yous page with classifieds from junxter. I want my users to be able to submit the ads via the web site and upon approval I let them go to the classifieds page. Anyone have something like that?