This repository contains a manual on how to setup a Meteor app on uberspace and a script to deploy the app. It is very basic and rough at the moment, but I hope it helps. You can even use it with HTTPS, although not many concers were put into security. Please feel free to improve.
The informations are compiled mostly from the documentation of uberspace.de
The deploy script works on OSX El Capitan and later.
Note: there is another apporach here: http://meteor.jens-doecke.de/ It installs meteor on the uberspace server (which I wasn't able to when I started meteor on uberspace).