This was mostly done over a weekend, working along with the great book Test-Driven iOS Development with Swift by Dr. Dominik Hauser. I'll be enhancing some of the features following the same TDD priciples shown in the book.
I thought this might be helpful for other people working through the book, as some of the code in later chapters is outdated for the latest version of Swift. Another decent resource is The book publisher's repo. I did find that some of the content covered later in chapter 6 was missing from this repo.