Been working on V1 of my WordPress plugin DB-Toolkit for a few months now.
Some background, its a WordPress plugin that enables you to build interfaces into database tables, both existing and custom. Its currently in beta version but after working it so long, I decided that V1 required a rebuild using the knowledge I gained. I decided to go custom interface for this rather than adapt it into WordPress UI. Mu thinking on this subject is that you need to retain some elements, mainly navigation style and colors, but a plugin should have its own feel. Sure a plugin needs to be part of WordPress but that doesn’t mean it should look like it.
Anyway, these are a sample of the toggle buttons for setting up a DB-Toolkit interface. the green highlight indicates its checked while the extended button with the “required” text expands on hover to reveal the text.