Installatron app for etherpad-like collaborative document editing


I’m wondering if there’s an app in the Installatron that allows for collaborative document editing. Something with the functionality of say Etherpad or Google docs. Got a group that wants to collaboratively draft a document(s) but really, really doesn’t want to have document stored on a cloud-based service they don’t control - hence Google Docs, Word 365, Dropbox Paper are all out.