Natural Cycles says contraceptive app is more effective than the pill
 

Contraceptive app Natural Cycles is more effective than the pill, according to the latest and largest study into the app's efficacy. After testing 22,785 women throughout 224,563 menstrual cycles, the startup found the app provided 99 percent contrac...

https://www.engadget.com/2017/09/13/...ive-than-pill/