Chorzzz provides a quick contact function for your family members. Simply tap the contact button and the standard Apple contact details page will be displayed. Call, text or FaceTime direct from Chorzzz.
You can find contact buttons on the Calendar and Chorzzz screens by tapping the user button at the top left. Alternatively they are available on the Family screen.
You'll need to allow Chorzzz access to your contacts to enable this functionality. Your contact information isn't used for anything else (or uploaded anywhere).