Nebulous Notes has been around since early iOS. It is one of those quiet and assuming apps in a wilderness of plaintext "notes" choices.
The developer has actively kept pace with latest iOS and was one of the first to offer rock solid Dropbox integration, which remains at the core of its functionality. In fact, the unique ability of Nebulous Notes to access, save and manage Dropbox files without a fuss rivals most notes apps.
Then with MarkDown, MultiMarkdown, RichText views, customizable keyboard shortcuts, pinch-to-zoom, optional auto-save, full-screen writing, you have the most essential ingredients needed for a robust notes app. There are many other welcome settings touches, along with the industry standard plaintext output choices.
Which brings me to the issue of customization. Theres a lot of talk about "productivity" and how "customization" gets in the way of writing. That may be a real issue, but I appreciate the abilty in Nebulous Notes to make the writing environment my own. If I AM COMFORTABLE with the environment, then the rest gets out of the way. Period. I am not a fan of apps that decide exactly what that looks like for me.
Nebulous Notes is one the best values on the App store, and frankly would still be so if priced higher, but dont let that fool you. Its up there the best available.
Tethys Sea Illustration about Nebulous Notes, v8.4