Driver.js

No, it's more than a tour library. Tours are just one of the many use-cases. Driver.js can be used wherever you need some sort of overlay for the page; some common usecases could be: highlighting a page component when user is interacting with it to keep them focused, providing contextual help e.g. popover with dimmed background when user is filling a form, using it as a focus shifter to bring user's attention to some component on page, using it to simulate those "Turn off the Lights" widgets that you might have seen on video players online, usage as a simple modal, and of-course product tours etc.