It looks really nice! (tested on Safari/Mac).

Have you considered adding a small popup encouraging people to set it as their home page? I use Ensō (https://enso.sonnet.io) in that manner occasionally.

Also, the "system" button disappears during writing (good), but it's hard to get it back unless I click outside of the editor. In Ensō, I re-enable it on any pointer move - I would suggesting doing something similar.

PS I work on somewhat similar tools (like the one mentioned above), esp. for loose, stream-of-consciousness style of writing https://untested.sonnet.io/notes/stream-of-consciousness-mor... then copy paste the text into obsidian.

If you ever fancy chatting about privacy-friendly, idiosyncratic/home-cooked software hit me up on sonnet.io/posts/hi !