Futon 2 is a Sammy-based UI for CouchDB. The hope is that it will eventually replace the current Futon in CouchDB.
One of the current limitations to Futon is that hacking on it is slowed by the setup time of compiling CouchDB, or symlinking Futon 2 into an existing CouchDB repo, or some other similar setup.
By providing this CouchApp directory, the hope is that anyone with client-side web UI experience can contribute to the further development of Futon 2.
First you will need to install CouchApp:
http://couchapp.org/page/installing
Next, create a DB with any name you like ('futon2' seems reasonable enough).
Then, within this directory, type:
couchapp push . http://localhost:5984/futon2
Last, visit your CouchApp Futon 2 at:
http://localhost:5984/futon2/_design/futon/index.html
Really last, enjoy!