If someone is still visiting this thread I'm still looking for a notebook app. Something to replace my paper notebook (because that can neither be backed up nor properly encrypted).

Keep is almost there with a combination of text and drawings. Missing: - links to other notes - checkboxes in between text (currently notes in Keep are either all checkboxes or no checkboxes) - tapping on tags should show all notes with that tag

OneNote is also almost there.

Samsung notes is also almost there.

Maybe what I wish most is some way to link from my calendar to Keep and back etc etc.

However, seeing how I still cannot even link to a mail in desktop Outlook I'm afraid this is only a dream.