Hey all,
we would be really happy to see Wiki.js - which is an Open Source project - to be available on the cloudron.io platform. For us this would be one "killer app". ^^
From wiki.js.org:
An open source, modern and powerful wiki app built on Node.js, Git and Markdown.
Amongst other considerations this is exactly what we demand from a modern wiki engine. We evaluated various solutions during the last couple of months and this seems to be exactly what we are looking for. A great alternative seems to be bookstack.
According to their Github project site the project is quite active, maintained and seems to have a solid user base.
And they offer ready to go docker images, too. 
So long!