I found another wonderful tool for writing, definitely worth sharing. It's called Haroopad.
It's an open source, cross-platform, markdown-based, code folding-capable editor. You can download Mac, Windows, and Linux versions from here.
The defaults seem to be set up for writers. You can toggle views: editor and HTML viewer side by side, or viewer (on the left) and editor (on the right) if you prefer that orientation, or just one or the other. It has a constant word count display on the bottom status bar. It has lots of themes. There's an automatic focus on the current paragraph.
The best thing is code folding. (This is a neat trick that turns a text editor into an outliner. By that, I mean that you can selectively hide and reveal big blocks of text, allowing one to see or rearrange the structure of a document.) I did have to toggle it on (on the Mac, it was under File>Preferences). It works reliably and consistently by structure (header level). I love outliners.
Other cool features: full screen editing mode, search, and some markdown enhancements for tables of contents, footnotes, and more. It's easy to bump the font size up or down. It also supports and correctly displays the github syntax for Tasks.
Bottom line: you wind up with a small fast, capable environment that allows you to quickly and efficiently generate text for the web.
Issues: it exports only to HTML. No spell check. You can work with more than one file at a time, but it's not tabbed (each file is a separate window). There's no navigation by structure.
But pretty amazing for free. I actually like this better than either Sublime Text or Brackets. HarooPad weighs in at 108.9 MB in storage. 9.3 MB of memory. It's a find.