Writing just seems natural from my iPhone. I think the reason I feel that way is because my phone is my primary point of expression for so many other things; Facebook, Twitter, photos, Instagram, texting & email. It just feels intuitive to type my thoughts onto a small screen where there is no web browser to distract me, no hacker news in another tab, no apps bouncing up & down asking for updates - just the notepad as a full screen application.
The constraints of the Notes app are actually well placed. No photos, videos or music. You are forced to embrace words for their meaning & construct the most powerful sentences within your reach. It might not even just be iPhone. It may be the new paradigm established in all iOS devices. This workflow, is so conducive of focus, it may end up on your laptop, desktop & any other machine intended for productivity. It very well may be the most powerful writing tool created to date.
At the least, it's very interesting to think about.