Create a list builder lightbox (placeholder) for Xenforo/Sendy

Hi, I run a community based on the forum software Xenforo ([login to view URL]). Now I need a list builder lightbox (that act as a placeholder) plugin that works with Xenforo. In the placeholder I will use form code from the list builder tool Sendy ([login to view URL]). Ultimately I want to be able to harvest e-mail addresses from people that visits my site but does not register as a regular member. Requirements on the plugin: * Must be developed according to Xenforo framework standards and best practice * Must be able (in the plugin options ) to set how often (in minute interval) the lightbox should pop up during a user session * Must be able (in the plugin options) to set whether the lightbox should pop up again at all during a session after a user has dismissed it with the click of a button. * Must be able (in the plugin options ) to edit the code that goes into the placeholder To qualify for this project you need previous experience of Xenforo plugin development that you must be able to show me. In the attached picture you can see visually what I'm asking for.