Ionic apps with remote live sync database on Raspberry

I have working Ionic App with great PouchDB plugin in it. Now I have to move database to Raspberry to work as database server for all Ionic Apps in local network.

My first guess is to just create CouchDB server on RPi and just connect it with PouchDB. Everything should be in realtime.

Now for many reasons I have to use MongoDB. Is there a way to accomplish realtime sync using MongoDB. In other words: Ionic App connects with RPi Mongo database and syncing in realtime ?

I’ve read about Meteor integration with Ionic, but it is little bit confusing to me, as server part is integrated in Ionic App ? Can I just create Meteor on RPi and somehow subscribe from Ionic App to that database just from Angular Factory ?