Calendar server
The options in calendar server are:
Automatically generate birthday calendar when contact birthdays are added
Send notifications for adding to events
Enable push notifications
Contacts
The contacts avatar image can be updated by syncing with social media link added
Circles
The settings of circles include
The maximum number of persons in a circle can be set
Allow linking of groups to add to a circle, so that groups also appear as search suggestions.
Skip invitation to users, for adding to a closed circle by the owner.