I'm looking for a javascript framework or tool that makes it possible to offer on an existing website, an assistant that will guide a new visitor. This would be useful for users new to a web application. The new user would click on the assistant icon, and the assistant would activate. This would display an overlay with a few use cases choices. The user would choose one use case, and the assistant would show him the way. The user would just have to follow and click where he is told to. He would be guided all the way with small visible popups indicating where to click now and what to type in some required fields.

Thanks for any tip !