Building flashcards manually in Goodnotes is great but I feel it a bit hectic. There may be an extra tool which can be used to mark sections of a page or whole pages to add them to the Recalling /Memorizing list. This should auto include all the items that we mark with the Recaller tool. One should be able to see all the hard-to-learn stuff at ones from each notebook/folder. In addition, a home screen widget may be created which would periodically display a section of the note for a quick revision which would be scientifically designed like Anki.