An app doesn't get lost like a notebook, it builds the calendar for you, it can give recommendations about when fertility is at peak (notebook never talks back), it's always with you when you're in the bathroom. A notebook can work.

Maybe think of it a bit like watching a movie on DVD and wanting to switch which room it's playing in. It's totally doable, but it's a hassle.With Netflix and a smart TV (or better set up), you get a pretty seamless experience. Add more blood, nausea, cramping, and depression to that scenario.

A place to keep track of personal notes and details should, you know, be personal.