Couch and Pouch really got a lot of things correct back in the day. However, Firebase runs off of MongoDB internally and as a result the realtime sync of Fireba

Couch and Pouch really got a lot of things correct back in the day. However, Firebase runs off of MongoDB internally and as a result the realtime sync of Firebase is quite distinct from Couch/Pouch. Firebase is ultimately the centralized authority, while with Couch you can have more of a Master-Master setup (which is a good thing).