Notebook.ai by Indent Labs

Notebook.ai is a smart notebook for worldbuilders that helps users create and organize their characters, locations, and items in fictional worlds. You can stick them all in universes to keep things separate, create relationships between them, or jot down any ideas you have about anything, any time.

In fact, Notebook.ai is designed to grow with your ideas and collaborate with you. It lets you develop your characters in depth, track every detail of their thoughts, appearance, family, and personality. Also, the platform allows you to immerse yourself in vibrant worlds with specialized notebook pages for your countries, cities, landmarks, and more.

One thing you’ll instantly notice is just how neatly Notebook.ai is organized, with an easy-to-grasp interface encouraging you to keep adding things to each section from the homepage. For instance, if you need to recall a small detail about a character, you can find it easily without interrupting your writing flow.

In addition (and naturally), Notebook.ai offers a built-in document editor to reference any aspect of any page in your notebook without losing your momentum. It will help flesh out your ideas by asking you questions about the pages you create to promote creativity and ensure continuity in your writing. Plus, it analyzes your writing with an AI that measures readability, style, emotion, and more.

Notebook.ai is free to use, with the core building blocks of fictional universes (characters, locations, and items), personalized writing prompts set in your world, unlimited document storage, and access to a thriving community of other worldbuilders. There is a premium subscription as well, which unlocks 25 additional page templates to use, each customizable and coming with its own set of writing prompts.