Eva is the easiest way to track your period. It tracks period cycle, ovulation days, and possible days to get pregnant. It marks the date of menstrual cycle and predict the next one. Eva also has a widget that shows the number of days that you have your period and the remaining days before your next cycle. Monitoring your period is important. There are many reasons on why you should monitor your monthly cycle, primarily health related. Eva makes it easier for you to track your menstrual cycle, menstrual duration and your most fertile days.