I use the excellent Ulysses writing app that allows me to take notes in multimarkdown. I use it as a slide over app so I can just slide from the edge of the scr

I use the excellent Ulysses writing app that allows me to take notes in multimarkdown. I use it as a slide over app so I can just slide from the edge of the screen while reading and never lose sight of the book. I create a sheet for each chapter.