[ggchappell]

What about Notepad? What do you want that it doesn't do?

I'm being serious here, by the way. Double-click on your notes file to open. Hit <Enter> twice to start a new note. It has all the features you mentioned (except for the Android compatibility). Are there others you want?

[glimcat]

Despite much fiddling with alternatives, this is still what I use. Since Windows 3.1, no less.

Portability is achieved with a notebook and pen.