If you're looking for a Story Path alternative, Subtxt is a good candidate. It offers a full narrative framework with tools like Narrative Agents, Subtxt Muse and Premise Builder to construct a story and fill in the holes. It's geared for screenplays, novels and plays, and costs $25 to $250 per month.
Another good option is StoryNest.ai, which offers a range of tools to craft compelling stories in many forms, including interactive fiction and nonfiction. With tools like AI-assisted editing, world-building tools and collaboration abilities, it's a flexible tool that can accommodate different narrative styles. You can try it free to see what it can do.
For fiction authors trying to break through writer's block and get more out of their writing, Sudowrite is worth a look. It uses large language models like GPT-3 and GPT-4 to help with idea generation, outlining, writing and editing. Sudowrite offers several pricing levels, including a free trial, so it's a good option to try out and see if it helps you get your creative juices flowing and your words flowing more productively.
Last, LivingWriter offers a clean interface to organize and structure your manuscripts. With tools like an AI Outline Generator, smart text assistance and export options, it helps you keep your work organized and polished. It also has a cloud-based design for easy synchronization across multiple devices, and a 14-day free trial before you have to subscribe.