SmartEdit Writer is a desktop app that offers a single place to keep all your notes, from text notes to images to outside links and other types of files. It has a built-in editor with many different checks, such as spelling, word repetition, and sentence length. Though these are fairly common, it also has a find and replace function, daily word tracker, and folders that can be nested without limit.
I think it's only available for Windows, but it could be available for other systems elsewhere.
The main draw for this one is being able to store everything in one application, and how easy it is to organize.