This book is now over 6 years old and web technologies have moved on. As a result, we are sunsetting support for this book including the tracking APIs that were used for the tracker and coffee run applications. Ottergram and Chattrbox should still work, though again the code is outdated.
We’ve released a new book specifically about React Programming, which is not dependent on any outside APIs. You can find it at React Programming: The Big Nerd Ranch Guide | InformIT and on Amazon and other book stores.