This is a Grand Meetup Project from 2016, by @michaelarestad (lead), @azaozz, and @georgestephanis to implement a WordPress Editor View for the Grunion Contact Forms module in Jetpack.
Further, we also wanted to improve the editing experience, by making it support inline editing -- that is, instead of opening a seperate popup to edit the form, it simply allows the user to modify the form directly in the editor flow. No popups.
To use this, it needs to be installed alongside Jetpack, with the Contact Forms module active. Then just go into a post editor and add a contact form!
https://videopress.com/v/fVfVICkl
To the best of our knowledge, this is the first example of anyone creating an interactive Editor View in TinyMCE in WordPress, rather than the typical methodology of invoking a popup modal.