I've been playing with a couple of tools for a while: osx notes, evernote, onenote etc., and I just returned back to Asana. Yes Asana. I know it's a pm tool, but actually, it is so good to store your notes, attach files. I can also share specific parts of my notes by putting them as subtasks. And now that Asana updated their UI it makes it even more pleasurable to use.