The original bullet journal method is paper-based, and its creator lays out reasons why it should be—the "friction" of the physical activity of writing and the time it takes is a key part of the method.
The Agenda app (https://agenda.com) comes close to bridging the notes-tasks gap in the same way as bullet journals. Emacs org-mode is the best simulation of bullet-journals, as far as I know, and there are are iPhone and iPad and Watch apps for org-mode.
The original bullet journal method is paper-based, and its creator lays out reasons why it should be—the "friction" of the physical activity of writing and the time it takes is a key part of the method.
The Agenda app (https://agenda.com) comes close to bridging the notes-tasks gap in the same way as bullet journals. Emacs org-mode is the best simulation of bullet-journals, as far as I know, and there are are iPhone and iPad and Watch apps for org-mode.