CouchApps are great. They require a little change of mindset. Because it's no longer about Programming Language->Queries Database->Generates HTML. With CouchDB it's actually more about You Have Data->Generate HTML->Done.
hckr.it is actually a CouchApp. While building it I realized that there are some things missing from the CouchDB stack, such as proper user registration, but all in all it gives you everything you need to build serious web-apps. Not to mention other exciting things that the master-master replication is able to achieve, especially in the mobile world, such as PouchDB.
The other exciting thing about CouchDB is that it's actually laying down the standards (the CouchDB protocol) for building correct APIs. So if you have an API, you have to document it and tell your developers how to use it. If your database is CouchDB, it's already using a well-known RESTful standard, and other developers that know CouchDB can pick it up immediately.