We were inspired by (this)[jsomers.net/blog/dictionary] blog post about the evocative 1913 Webster's dictionary and how it finds the essence of words as opposed to rigid definitions.
We thought "gee it would be nice if my word processor had this dictionary" and then from there we envisioned another set of metrics that would be helpful for a creative writer.
Our target user is a creative writer looking not for an analysis of whether their writing is "good" or "bad" but instead what the writing's "makeup" is. In this way a user can look at how their metrics (vocab diversity, avg sentence length, passive voice usage, etc) change as they write and how writing they consider "model" for themselves compare.
We have some fun metrics as well such as grade level (Flesch-Kincaid) and "average year" of the vernacular (this is a rough metric based on the peak popularity of each word over time via Google's n-gram corpus).
We hope this becomes a helpful tool for creative writers.