Annotations/Sticky Notes for Adventures

I'd really like there to be a way for me to add sticky notes to the adventures, so that I can have the full text in front of me while also having my own comments for when I'm running the games. It would be helpful to be able to turn them on/off. I'm not sure how it would translate to mobile though. I would definitely buy more adventures and things if I could use D&D Beyond as my single source of prep.