I followed the instructions outlined online at https://github.com/noflo/noflo-ui to setup the Noflo-ui locally on my device. The build goes fine.
However, when I access the webpage I don't see any local runtime registered.
Do I have to install a runtime manually?
Yes, you'll need to setup a local runtime manually. Please take a look at the following article for instructions on how to setup a NoFlo runtime with Flowhub:
http://docs.flowhub.io/article/84-getting-started-node-js