Period Tracking
"Peri is a period tracker application. It has all the features that help you track your cycle.
The app shows the number of days before your period, the current cycle day, the possible next period date, a history of previous cycles and more. It also tracks the current phase of the cycle and displays information about this phase and the symptoms that a woman may feel during this phase.
Peri is open-source and built with React.js."