If you want a service to work with others to create and profit from intellectual property like characters or plotlines, Novelcrafter could be a good option. This novel writing suite includes a full-featured writing environment with a personal Wiki (Codex) for notes, different writing modes and some AI tools. It's geared for solo writers and collaborative projects, so it's good for either approach to your creative work.
Another option is Heyscribe, which offers a variety of tools to manage and profit from your work-in-progress content. In addition to project planning and management tools like Trello, Heyscribe lets you sell premium content, offer memberships and run crowdfunding projects all in one service. The idea is to help creators establish a lasting revenue stream and better connect with their audience.
If you're interested in the nuts and bolts of storytelling and consistency, Subtxt offers a collection of AI tools to help you build and refine your story. It includes tools like Narrative Agents, Subtxt Muse and Premise Builder to spot holes in your story and fill them in, and it's geared for screenwriters, novelists and playwrights. By using AI to process storytelling theory, Subtxt tries to preserve your voice even as it helps you improve your narrative.
Last, Pirr is an AI-powered storytelling service that lets you create personalized romantic stories on your own or with a group of friends. With modes for discovery, story generation, creation and publication, Pirr has strong privacy controls and a feature-rich app and web interface. It's a good option for creating collaborative storytelling experiences.