Developer here. The most obvious thing is the attention to aesthetics and user experience. The entire point of Notes was to create an application that invites people to write.

This is why:

- As you type, unnecessary widgets disappear so you can focus on your text.

- The app doesn't allow you to customize much; there is a pre-defined selection of fonts.

- But at the same time, Notes is still powerful enough. The website demonstrate most of the features well: https://www.get-notes.com

I think this type of opinionated design makes people more focused.

"The more things you can do instead of writing, the more tempted you will be to do those things instead of putting words on the page."

You can also check my ideas for the future of Notes here: https://github.com/nuttyartist/notes/wiki/Vision.