AS OF MAY 2016, THIS PLUGIN IS NOT BEING MAINTAINED AND WILL NOT RECEIVE ANY FUTURE UPDATES. 
CONTACT ME IF YOU’D LIKE TO LIST AN ALTERNATIVE HERE.
Shows word and sentence counts plus a readability analysis of the post 
currently being edited using three different readability measurements.
Readability analysis is an attempt to show how difficult a text is to read. 
There are several methods of doing readability analysis. The most popular 
methods are used here. The Flesch and Flesch-Kincaid methods use formulas based 
on the average number of words per sentence and the average number of syllables 
per word. The Gunning-Fog method uses a formula based on the average number of 
words per sentence and the percentage of “hard” words (words with 3 or more 
syllables) in the passage.
Both the Gunning-Fog and the Flesch-Kincaid give a score that is the number of 
years of education the reader must have completed to understand the text. 
Different types of writing calls for different scores. Technical subjects may 
require a higher level of education so a higher Fog or Kincaid score is 
acceptable. Informal writing may try for a score in the 7-10 range. The Flesch 
score is a percentage. The higher the value, the better the readability.

FD Word Statistics Plugin

Shows word and sentence counts plus a readability analysis of the post currently being edited using three different readability measurements.

room34

NEW IN VERSION 2.0.0: Users with a custom role will now only see the posts or pages they are assigned to. We’ve also streamlined the admin interface for easier configuration, and included additional instructions to help you get the proper capabilities assigned to your custom roles.
Custom Access Roles allows you to create, edit and delete custom roles for editing content. It was created to fill a need for a role editor plugin that is focused on providing easy-to-use admin tools for restricting content editing access. It is not concerned with restricting viewing access on the front end.
It is specifically intended for large sites with multiple content editors, where editors (by role, not individually) need to be restricted to only being able to edit specific areas of the site.
With this plugin, administrators of large sites have relatively fine-grained control over which user roles can edit which content, making it possible to manage a team of editors without concern that they will (accidentally or deliberately) edit content they should not have access to.
You can define a fully customized set of capabilities for each role, along with defining a specific set of post categories, pages, and custom post types to which those capabilities apply. For all other content, the role will have read-only access.
Custom Access Roles provides an easy interface for managing these roles and capabilities, with checkboxes for each capability grouped by the standard roles they’re associated with, plus checkboxes for each post category, page, and custom post type, presented in an organized hierarchy.

Custom Access Roles

Create custom roles with editing capability for only specific pages, categories and post types.

FD Word Statistics Plugin vs Custom Access Roles