ZenPen is great, but there's one thing I'm missing though.
What I'd really like to see is a focus mode like in iA Writer.
For those who don't know iA Writer's focus mode, it basically just makes the current sentence stand out more by reducing the contrast of the other sentences.
So that looks like this:
http://imagr.eu/up/52bab340db21e_Capture_d%E2%80%99%C3%A9cra...