A short, simple course that allows you to create a simple wiki in your development environment ( on you computer as opposed to the web).
It gives an introduction to HAML which I hadn't heard of before and seems on first glance to be fairly simple to read and write.
When I went to try and deploy this app I realised that the devise gem, which is used to authenticate your users must be set up differently if you plan to deploy the app to the web. This isn't much extra work but took me a while to figure out how to do this.
Sign Out - The course doesn't include a sign out route or button so I had to put that together myself.
Overall these are minor quibbles in what is a quick and fairly easy guide to an interesting application.