I recently downloaded iA Writer because it was a recommended application of the Mac App Store. It's a clean little application that allows you to write your thoughts on a clean slate without much of the formatting stuff of word processing software.
This is on Window mode. You can also synch it using iCloud.
This is the iA Writer on Full Screen mode. No icons, no nothing. Just like a paper to write on.
If you have 8.99 dollars to spare, download it - but only if you plan to do some writing. Nothing out of the ordinary, just a clean and simple interface, which is how I like my apps.