Are there any plugins out there (similar to Swagger) which provide the ability to document HATEOAS APIs?
The Swagger interface is quite good but it doesn't have level 3 REST support.
After further investigation I discovered HAL-browser (https://github.com/mikekelly/hal-browser) which is quite good. Although, your API must return content-type of HAL for it.
You don't need to configure anything on the server for this tool. Just open it in a browser and point to your API.