I really liked this book at the time because it was a beginners introduction into the basics of functional programming (monads, functors etc.) It was easier to grasp because of examples of practical applications with the Cats library.
Awesome read, it helped me to pick up the scala syntax. I come to scala from haskell so I already knew the concepts and I only needed to learn the scala way of expressing them. Thanks for the book, specially because is free!
Straightforward explanation of the capabilities of the Cats Library without wasting time explaining every detail of Scala language syntax. Great read for someone with 3+ months of hands on Scala experience.