Very slick, but also very slow. Occasionally I have to run a command twice for it to register. Also, it's strange that git's output isn't colorized, considering the "Success!" messages are.
All the commands are implemented on the remote end (hence the latency), and some of them look like they are a limited node.js reimplementation (git is mostly the real deal, though the command list is whitelisted). I would be interested in a version that runs locally in JS/Linux.