Write App - No-distraction writing tool for your productivity.
Evernote - Bring your life's work together in one digital workspace. Evernote is the place to collect inspirational ideas, write meaningful words, and move your important projects forward.
Hemingway - Hemingway App makes your writing bold and clear.
Joplin - Joplin is a free, open source note taking and to-do application, which can handle a large number of notes organised into notebooks. The notes are searchable, tagged and modified either from the applications directly or from your own text editor.
ProWritingAid - For the smarter writer. A grammar checker, style editor, and writing mentor in one package.
Google Keep - Capture notes, share them with others, and access them from your computer, phone or tablet. Free with a Google account.