Menstrual tracking applications allow women to track their menstrual cycles and receive a prediction for their period dates. The majority of apps also provide predictions of ovulation day and the fertile window. Research indicates apps are basing predictions on assuming women undergo a textbook 28-day cycle with ovulation occurring on day 14 and a fertile window between days 10 and 16. There has been a phenomenal worldwide increase in the development and use of mobile health applications that monitor menstruation and fertility. Critics argue that many of the apps are inaccurate and lack evidence from either clinical trials or user experience. The aim of this scoping review is to provide an overview of the research literature on mHealth apps that track menstruation and fertility. This study sought to review apps designed to track women’s menstruation or fertility with a specific focus on the evidence. In this review each article was subject to the inclusion and exclusion criteria.