That sounds interesting. Have you compared your service to pouchdb and gun? Is it possible to use icepeak in offline mode and automatically sync when getting online again?
PouchDB is CouchDB-Protocol implemented in javascript so you can run it wherever there is javascript, not just as a client. If you want to have a backend, you can use any DB that supports that protocol (there are several), which includes using a PouchDB instance run by node.js.
That depends on your use case since Firebase is more than a database. Since CouchDB is from 2005 and Firebase is from 2011, it is in comparison a very mature product and protocol worth trying.
Do you still need CouchDB on the backend?
I see from the mailing list it is still a very active project, which surprised me.