I am (very) biased but Couchbase has a pretty solid Mobile offering for native apps. I have worked on the Sync Gateway component responsible for replication for the last six years.
Sync Gateway still maintains a CouchDB-compatible REST API, and PouchDB _mostly_ works thanks to that, but there are some corner cases and features that PouchDB does not support so YMMV with it. Our native app libraries have used a more performant websocket-based replication protocol for many, many years now, and I'd really love to have the time investigating a PouchDB adapter using this WS protocol instead.
Sync Gateway still maintains a CouchDB-compatible REST API, and PouchDB _mostly_ works thanks to that, but there are some corner cases and features that PouchDB does not support so YMMV with it. Our native app libraries have used a more performant websocket-based replication protocol for many, many years now, and I'd really love to have the time investigating a PouchDB adapter using this WS protocol instead.