What's the best ultra-simple app for note-taking on your phone?

I just want to click the app and start making a note, then organize it.

i’m not sure if android has a good equivalen

but on iOS i use apple shortcut to trigger a popup (see picture)

the only thing that this does is it saves some text to a predefined location on my file system 

in my specific case as .md file inside my obsidian folder

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Orange DAO 🍊(F1) fellow

That looks perfect! So it's a shortcut for Obsidian?