Focuswriter is a free, open-source writing and composition program developed by Gottcode that is notable for two features; immense visual customization of the GUI and layout, and its "zen" nature. It has all the baseline features you would expect in a modern text editor: rich text, spellcheck, wordcounts, find and replace.
There is a bar at the top, and the bottom. Each bar and every option therein, reall everything except for the text page, is hidden until you mouse over it. If you want, you can set the bar at either the top or the bottom to always be visible, and customize what is and is not on each bar. It's designed for pure distraction-free writing, "focus" writer.
What makes it truly powerful is some of its extra features designed to encourage daily, consistent writing. You can set a "daily goal" of a certain number of pages, words, or minutes writing, and it will show you your progress toward that goal in the bar at the bottom. It will also log the amount of writing you do each day, and record a "streak" of how many days in a row you meet your writing goal. You can see graphs and charts of all this information (time written, words/pages written), and it can also do focus timers. You can tell it how you want it to track words, or paragraphs, the completion threshold for streaks, it can even make typewriter sounds. It's friggin' awesome.
The biggest appeal for me, like HUGE, is its visual customization. You can change the background behind the text page to any image or color, as well as the text transparency, font, text color, page color, paeg transparency, page width, page corners (rounded or sharp), margins, line spaceing, paragraph spacing. It's insane how much you can customize. You can set a different theme for each mood, each scene, literally whatever you want. ADDITIONALLY, you can export themes and import them on any other devices.
It runs on Linux and Windows. Unfortunately Mac users miss out on this awesome software. and it's FREE! I would legitimately pay big money for software like this but it's free and open-source with an optional tip.
You know, now that I think about it, I should send the developer a tip. Buy him a coffee or something.
Here is a link to the download webpage.