Although this is very similar it isnt it.
The one I used even had some of these wallpapers but a really easy UI and you could add your own wallpapers all through gui without terminal.
Starting to think i dreamed it but my wife insists I didnt shut up about it when I had it the first time.
Ive had a galaxy tab for a bit over a year now and use Notewise.
Its not foss but fuck me its the most comprehensive note app ive found for use with pen.
I use it to mark up construction plans, edit PDFs, sign documents, design things with its protractors and rulers, take notes, read manuals, its really above the rest in every way.
I do use Joplin for general text note taking in a notebook style but Notewise for anything and everything else.
edit - it also saves documents in i believe vector format so you can fully zoom in to your writing / highlighting and its never blurry. I found that samsung notes was absolutely horrible after you exported anything to pdf or image.