I am looking for a self-hosted app with just a single, endless notepad page and an app for iOS. Or a local app that plays well with GDrive, Dropbox etc)

I know I can do the bookmark thing, but it just isn't as nice as a dedicated app. I don't want to mix it with all the other websites I open.

I already have note-taking solutions like Trilium that are useful for organizing information. But I also often write down random thoughts and stuff that don't have any particular place.

I don't want to just create a "miscellaneous" section in Trilium, because I like to keep Trilium open to notes relevant to the task I am doing, and switching back and forth between notes is distracting to me.

I want something that's like the notepad app that used to come with MacOS (maybe it still does, I haven't used a Mac lately).

Ironically, I got into the the whole knowledge manager/hierarchical notes thing because my notepad was getting huge and I could never find anything. But now that I have a satisfactory way to organize more structured information, I want a tool to record interesting bits of my stream-of-consciousness in a way that doing so is a minimal distraction from whatever I am supposed to be doing.

I'd like it to save to a plain text file for easy portability.

So in other words, I want a text/markdown editor that only ever has one document. It needs to be extremely light (as in, not an Electron app). I want to open it on any device, wherever I am, write down my distracting little thought, and then go back to whatever I was doing.

If I can change the display font and size in the app without zooming, that would be nice but not mandatory.

Is there anything like this?

I see a few things in Awesome-selfhosted like Meemo, Minimalist-web-notepad and Flatnotes, but nothing seems to be quite what I want.

PS: I know there are a million threads about note-taking apps here, but I wasn't able to find one about this specific need.