I’ve run koboldcpp on a steam deck. You have to stick to small model files, of course, like maybe 4Gb, but you can get decent speed if you do.

And Edge Gallery on Android can run models locally on a phone.

I use Obsidian as a OneNote replacement because it’s built around markdown, which is just a a text file that includes structure and formatting.

I don’t use their subscription syncing service, just sync files to my own phone and server. Obsidian is great for organizing, but I can still read all the files as text.