I started building my app today. I learned a lot about sending notifications to iOS devices using Firebase. I learned a lot of other things about other stuff as well as I set up all of my tooling. There should be a course just for tooling included in the Nanodegree.

It is somewhat interesting to note that, in all likelihood, you will learn far more outside of the Udacity video lectures than inside. I think that to a certain extent, this is just the nature of the beast. Most people learn more by doing than by watching.