S Memo is actually the predecessor to the S Note. This was only found on the original Note. S Memo was replaced by S Note in later Notes.

I am assuming you already tried the S Note widgets which fell short of expectation?

I use LectureNotes which I assign pages within my notebook as a widget. When the widget is tapped, it will launch the app directly to the page which you can immediately edit and work on. Not sure if that is something you are looking for? Though it sounds like you are looking for something like Post-it notes too.

Also, LectureNotes has a lot of options that can take time to go through. But once set up to your preferences, it is a decent note taking app. But that will be dependent on the user.

The trial version can be found here:
https://play.google.com/store/apps/details?id=com.acadoid.lecturenotestrial