Mac only: Ommwriter takes distraction-free writing one step further by setting it against a serene winter background and calming music, designed to help you relax and concentrate at the same time. Cheesy, perhaps, but possibly effective.
The full-screen text editor isn't exactly powerful, but it will certainly work well enough, especially if you're writing a longer document that doesn't require a lot of formatting. You can choose from three font types, three font sizes, seven different background sets or background music, and seven keyboard sound effects (and, yes, you can turn them off entirely). You can save your documents in either Ommwriter's own .omm document format or standard .txt. We're at a loss for any reason to save in .omm, considering Ommwriter can open and handle plain text documents just fine, but it's there. After you finish the heavy, focused writing in Ommwriter, it's easy enough to move that text to a more feature-filled document editor for final touches, revision, and collaboration.
Ommwriter is a free download, Mac only. Thanks, John!