Skill updation with Hermes Agent to tailor personal skills; smart context injection from previous chapters; story wiki/Story codex+Timeline; all of this linked and optimised via skills.

You have made an amazing app; there are a few improvement elements you can add without disrupting the existing layout, which is almost perfect.

1.) Text completion using a special key setup like double spaces or //;

I will write half a sentence and let it be auto-completed using text completion. Much like what QuillBot does in QuillBot-Flow.

2.) Skills + Hermes-Agent is a perfect combination you can have for personal skill creation. It will accommodate the user's writing style and, over time, learn and build skills according to the user's preferences for the story and writing.

3.) Timeline for keeping track of the flow of the story.

4.) Story wiki/codex for world-building data about characters and story.

Using any or all of these will allow for more targeted writing.

You can also have a one-time fee for the platform and let the user use his own key; many would like that also.