I have looked at applications that help you write without distractions, like WriteMonkey and the cloud-based QuietWrite. But they have their limitations. WriteMonkey, Q10 and other distraction-free writers save the text in a .TXT file, which many people may not like.
You can turn Word into a distraction-free writing app too, using a simple add-in called Writespace. You get the typical black-background-with-text interface, coupled with the advanced spell-check and other Word features.
You just go to this website and download the installer. It guides you through a simple setup. It integrates with the latest Office versions as well as Office 2003.
Writespace can find text, spell check, go to line and more. You can also customize the colors and add in a margin.
It's a perfect add-in if you are looking for the perfect distraction-free writer that saves in Word formats and has advanced Office features as well.