Cannot_launch_webapp_on_ubuntu_12.04_using_ppa.mdwn

Hi, I have installed latest version from https://launchpad.net/~rubiojr/+archive/git-annex, that is git-annex version: 3.20121017-ubuntu1ppa1~precise
When running git annex webapp I get 

git-annex: unknown command webapp

I only installed git-annex. Are there more packages to be installed to make it work?