Every time I "saved" any changes, a dialog box popped-up encouraging me to register the free version.
I went to the website and looked up any solutions for this and couldn't find anything. I ended up uninstalling it.
I think what you are writing is completely misleading to potential users.
In fact you just needed to choose the package the form was stored into. That's the same like categories for joomla articles. I think it is not that hard, isn't it? A quick look into the getting started guide would also have revealed it.
This extension is fully working without forcing anybody to purchase.