Scrivener: "Scrivener (/ˈskrɪvənər/) is a word-processing program and outliner designed for authors. Scrivener provides a management system for documents, notes and metadata. This allows the user to organize notes, concepts, research and whole documents for easy access and reference (documents including rich text, images, PDF, audio, video, web pages, etc.). Scrivener offers templates for screenplays, fiction, and non-fiction manuscripts. After writing a text, the user may export it for final formatting to a standard word processor, screenwriting software, desktop publishing software, or TeX."
Outlining Your Novel Workbook from (our own) K.M. Weiland helps with novel structure.
ProWritingAid is kind of like Grammarly on steroids. "ProWritingAid analyzes your writing and produces reports on areas such as overused words, writing style, sentence length, grammar and repeated words and phrases."