I just downloaded iA Writer for my iMac. It's a completely stripped-down writing app that has only a handful of settings (fullscreen / spelling / word-count) as well as a unique 'focus mode' which, when enabled, emphasises your current sentence. The idea is that you can focus on your ideas and your words without distraction. It's quite beautiful.
At £7.99 on the Mac App Store, it's also quite pricey (comparatively). Simple word processing systems are very trendy these days, which is good, I suppose, if they get folk thinking... but bad if all they do is encourage further procrastination by creating an unquenchable urge to find the 'perfect' writing app. I guess I'll need to wait until I've written a bunch of stuff (or not) to know whether I've been duped into paying a premium for what's effectively TextEdit.
If I do write more because of iA Writer, even just a little, then I consider it money well spent. A good idea is well worth £10.99.