Very nice plugin!
But I noticed it doesn’t follow widget standards. Themes use to set some configs, like main list classes, widget title’s before and after, etc.
Your plugin doesn’t follow these standards, so its widget is shown different than others. In my theme, title doesn’t have background and lists are broken, due to lack of classes.
Instead of following standards, you set these stuff in widget config. But for exemple my theme’s wisget’s title is h6, while your widget has h2 hardcoded.
I’m not complaining, I liked it very much and it has all the logic. I’ll probably fork it into a brand new plugin taking it’s logic so that I can use it :)