Is there any stable nosql database for iOS except for Couchbase?

Is there any stable nosql database for iOS except for Couchbase? Couchbase is now a beta version which i don't want to use on a app with many users.(Although i like Couchbase very much)

Any suggestions? Special Thx!

There are several projects to get a CouchDB-compatible API available on mobile devices.

• TouchDB, a native iOS build
• PouchDB, an HTML5 implementation, for web and PhoneGap apps