The overall idea is to make it as easy as possible to go from source code in a Git repository to a running application. Shipway makes heavy use of the GitHub API and tries to act as a thin layer on top. It sets up a GitHub hook to trigger a Docker build when you push commits. It hosts the resulting Docker images in its own registry, and can execute webhooks after successful builds.
There are a few similar products out there, namely Docker Hub and quay.io. Both are interesting in their own way, but neither allows you to carry over your GitHub organizations and teams and use them with Docker repositories.
I'm excited about all the container hosting options that are starting to mature. Once the Kubernetes API stabilizes, it seems like it could become a standard interface for running containers on any cloud. The EC2 Container Service also looks interesting.
Anyway, thanks for checking it out!