If you're looking for an app that uses AI to create personalized stories based on your preferences, Pirr is a great option. It lets you create romantic stories with very little input, asking questions about things like character names, pronouns, tags and vibes. The app has modes for Discover, Generate, Create and Publish, so you can get the full story experience. It's got an NSFW mode for adult content and is private by default.
If you're more interested in novel writing, Novelcrafter is a full-fledged writing environment with a personal Wiki to keep track of story details. It's got AI tools for outlining, editing and writing assistance, so it's good for solo or collaborative projects. The service lets you customize AI prompts and offers different pricing levels.
Last, Storyville is good for parents who want to create personalized bedtime stories for their kids. It creates interactive stories based on the child's name, gender and appearance, with illustrations and educational content. The service offers audio narration and a free trial for new users before requiring a subscription.