It is fun to have my blog posts reviewed by the Hemingway App. It appears that I write at the 6th to 8th grade level and the prose is pretty simple. I may actually try this with my work emails and presentations to make sure I am at the 3rd to 5th grade level like I am supposed to be. Though I am not sure if the auto-generated review of style and simplicity can be taken too seriously.
When I entered an excerpt from James Joyce's Ulysses, it flagged only a couple of sentences as hard or very hard to read. The overall readability was calculated to be at 7th grade level. I don't think anyone who has tried to read this book (several times) and failed will agree with that assessment. Maybe what appears "structurally" simple does not always translate to real simplicity - in the case of a book, the ability for the average reader to connect with and follow along the plot line. I was not able to do that with Ulysses twenty years ago on my first attempt or any time since then.