Somebody recently pointed me to tools for writing prose, several of which are in fact atom packages. One of the tools that this person showed me is another editor called hemingway: http://www.hemingwayapp.com/
It has a cool feature that I’d love to have in the form of a package for atom. Basically what it does is very simple: it highlights problems using different background colors. E.g. long sentences get marked red or yellow depending how long and complex they are.