I've created a visual studio extension with some nice refactoring features via a Code Refactoring (CodeRefactoringProvider) roslyn project, but there isn't really anything to it in terms of adding tooltips or menu items or doing something on startup.
If I wanted to do something like add a settings menu or tell the user that they're on a trial version, how/when could I even do it? Even though I'm working in a vsix, events don't seem to be exposed anywhere.
Do CodeRefactoringProviders run in a bit of a sandbox? Because I like the way it consumes my class, shows the user a preview and it fits into the editor amazingly, but of course I'd like more control because after all, the root of what you create is a VSIX which can do almost anything in the visual studio environment.
I'm sure I could limit the # of refactorings and show a popup.. but I'm fairly certain people would send death threats.
You can add other elements in just the same way you would in any other vsix in a Roslyn vsix. There are various ways to do this, such as creating a Visual Studio Package, using an ITextViewCreationListener, etc.
One sample that I created showed how to integrate a Tools Options page with a Roslyn code issue at http://code.msdn.microsoft.com/windowsdesktop/Roslyn-Code-Issue-with-84d792dd (wayback machine link).