If you're looking for a storytelling app where you can customize story elements and share with a community, Pirr is a great option. This AI-based service lets you create personalized romantic stories, by yourself or with others. With modes like Discover, Generate, Create and Publish, you can read, write and share stories based on your interests. The app has strong privacy protections and an NSFW mode for more adult content.
Another good option is Novelcrafter, an everything-and-the-kitchen-sink novel writing tool. It's got a personal Wiki (Codex) for storing and tracking story details, and several writing modes like Plan, Write, Tinker and Review. Novelcrafter also offers AI tools and customizable tags and labels, so it's good for solo and collaborative writing projects. The service offers a 14-day free trial, so you can try it out before you subscribe to a plan.