I'll say up front that I'm skeptical of claims of "distraction-free" writing environments, especially the super-precious over the top ones, for all the reasons that Merlin Mann has laid out in various easily findable places on the internet.
That said, I think I really like iaWriter for Mac. And I say that even though I've basically abandoned iaWriter/iPad in lieu of somewhat more functional options, like Nebulous and Textastic. But on the Mac, I already have more functional options, and although I was originally skeptical of when I might use iaWriter, I think I have found a niche for it for quick writing tasks like blogging and taking notes.
Having used iaWriter for about a week (this post, plus the last few daily posts, plus some other note kind of things), I think that the "distraction free" frame is a little misleading. iaWriter is not distraction free in the sense that a white room is distraction free. It's distraction free in the way that a race car is.
Forgive me for this metaphor, I'm not a big car guy. It feels like every part of iaWriter has been precisely engineered to reduce friction and become fastest possible path between your brain and a text file. And if that means that some luxuries have been jettisoned, like cup holders, or comfortable seats, or the ability to change fonts... well, nobody expects a race car to take them to the grocery store.
It really is a beautiful app. I still really love the Nitti Light font and although it's minimalist, the type is crystal clear, easy to read. The thing loads almost astonishingly fast, the background is subtly textured so you know it's there, but doesn't call attention to itself. The cursor is a big thick blue bar, easily visible but not garish. The window drag bar is small, and fades away if you start to type. There are no preferences, and only a few toggleable menu items.
The width of the page is set to 64 characters, and you can't change it. There's a nice margin around the text, but if you go to full screen mode, it looks goofy -- a huge margin around a strip of text. (Actually, I think one of the reasons why it feels like I can get text down on the page so quickly is the 64 character limit is smaller than my normal default of 80 which means that I run through lines faster than I otherwise would. The font is big -- I normally type with a big font, and this feels natural to me. Again, easy to read. When you hit the bottom of the screen, the cursor and the writing space snaps back up a bit (in focus mode, it snaps back to the middle of the page, which I really wish it would do in regular mode as well).
There are keyboard shortcuts to move up and back one sentence, which I guess is the Mac analogy to the iPad version's special keyboard navigation. And there is focus mode, which fades out everything other than the current sentence. I don't know about that one, I think it pushes things too far, but if it works for you don't listen to me.
iaWriter has a kind of semi-wysiwyg mode based on Markdown, where things that are marked as bold or italic in Markdown will have that font applied, which is nice. Also, when writer sees a line that starts with a Markdown decorations like # for headers and * for bullet lists, it will put the decoration in the left margin so that the text remains lined up with other text. The effect is interesting, making it easy to scan the document for headers, but the fact that all header levels get the same font treatment is a little odd.
What I can say about it, is that using it for five minutes made me want to find something to write so that I could use it some more, and even try and figure out a way to work it into my blogging workflow.
New files open in a window that is only a few lines high, which I think is a little strange.
It remains irritating that you can only open files that are of type .txt and .markdown. I'd love to try some others.
It's a major irritation that it does not remember what files were open when you reopen the app. Nor, somewhat astonishingly, does it remember the settings for spell and grammar check. This will apparently be fixed in a future release.
A couple of spacing glitches, it fades the last line to grey at the bottom of the screen, which is kind of cool, except when you are actually typing in that line, in which case it still fades the line and it's a pain. The docs claims that it maintains indentation if you indent a little, like for a Markdown code block, but I've found that intermittent in practice.