I have installed Gravity Forms and the YMLP add-on and am experimenting with my first feed. It all seems to work like a charm except I am missing one essential piece of functionality that YMLP forms offer and I can't see how to set it up through the forms feed.
It is regarding the ability to have a user select a group or groups in a form. We use this functionality to have a user select to be part of the "newsletter group" yes or no.
In YMLP it is the 3rd section in forms design (I have it in dutch and don't know what it looks like in english) after the fields and hidden fields sections.
I attach a printscreen: http://screencast.com/t/hpeoGQC24k
Looking forward to your response and a big thumbs up for the add-on already!