Fine-tuning each app to your liking
Every app on test, aside from Ommwriter, has focus (or highlighting) modes and typewriter scrolling. They differ in the fine details, but it’s elsewhere that variance is more obvious. iA Writer has a take-it-or-leave-it interface, bar adjusting text size. Byword gives you custom fonts, two themes and three column widths. Ommwriter has three themes, four font options, a resizable writing area, and background audio and typing noises. Focused offers six fonts, three themes, audio, and the choice of ‘responsive’ text sizing or four specific font sizes and three column widths.
WriteRoom and Ulysses go for fullon theming. The former app enables you to edit sounds, backgrounds and text styles, allowing alternate settings for full-screen and windowed modes within the same theme. Three of the four default themes are ropey, so this is just as well. Ulysses looks great to start with, and provides multiple mark-up and export themes (for HTML, ePub and rich text). In addition, you can adjust the font and typography.
WriteRoom makes it possible to create your own themes, which can vary wildly.