Very simple and easy. As an Educator in English and Social Studies, I have often worked hard to find reading levels for digital materials. If you highlight the text, then click the icon, it shows you the grade level equivalent. I hesitated to install it because of the low review score, until I realized the low-scoring reviews were from people who ironically were struggling to read the instructions.

Does nothing!!!

The extension only does one thing, but it does it simply and unobtrusively. The Flesch-Kincaid reading level appears as a red number on the extension icon for the webpage you're browsing. Definitely useful when selecting sources for students.

Just a button, doesn't do anything!