There is already a calendar application that tracks a woman’s cycle. I know about this because my friend says he use it to track his wife’s cycle and he knows what days she’s going to be in the mood based upon her being mid cycle
Yes, there are effective, do-able calendar approaches, and they’ve been getting better and better for the past 50 or 60 years. This app seems to be just the latest in making things super-accurate and at the same time not dauntingly complex.
You can use it for either postponing or achieving pregnancy.
Or, as you say, for figuring out when the wife is likely going to be mmmmmmmost mmmmmmmmellow toward the couple coupling thing.
Mmmmmmmm...