Recently, Reed Esau has amassed quite a list of Vim plugins for writers.
:colorschemeto bring broader theme support for changing Vim’s appearance based on your task and environment.
vim-pencil aims to make Vim an effective tool for writing prose, bundling a handful of tweaks to handle (and even detect) line wrap modes.
iA Writer is an elegant word processor, marred only by its lack of Vim. It does have a nice color scheme, however.
vim-wheel provides screen-anchored cursor movement for Vim, merging
k with the scrolling of
vim-lexical extends Vim's built-in spell-checking and thesaurus/dictionary completion.
vim-quotable extends Vim to support typographic ‘smart’ quotes.
vim-textobj-sentence improves Vim's native sentence motion command.
vim-litecorrect provides lightweight auto-correction for Vim.
See the complete list on Reed's GitHub profile.