If you want a one-stop shop to create an outline, write your novel and review your draft, Novelcrafter could be the best. It's a full-featured writing environment with a personal Wiki for storing story information, multiple writing modes and AI tools to help you along the way. It's got revision history, tags you can customize and a variety of pricing levels to accommodate different needs, so it's good for solo writers and collaborative projects.
Another good option is LivingWriter, which is designed to help novelists organize and structure their manuscripts. It's got a clean interface with a drag-and-drop chapter organization, an AI Outline Generator, smart text abilities and a cloud-based sync system that works on multiple devices. The app can export in a variety of formats and has a variety of subscription levels, including a lifetime option.
Subtxt is another option, particularly if you want help with narrative consistency and spotting plot holes. The tool uses AI to create story beats, develop narratives and analyze thematic structures. With tools like Narrative Agents and Subtxt Muse, it's designed to help novelists, screenwriters and playwrights develop their stories while maintaining their own voice.
Finally, Sudowrite has a variety of AI tools to help you at every stage of writing, from idea generation to editing. It's got tools like Describe, Write, Expand and Rewrite designed to help you be more creative and productive. Sudowrite also offers customizable dark modes and project organization tools, so it's a good option for fiction authors who want to try to get more out of their writing.