In order to sync CircleBack to your local address book, please do the following:
- Open up the CircleBack Application
- Tap on the Settings icon
- Press "Sync"
- Use the toggle to enable "Sync"
- Make sure that "Mirror Contacts on Mobile Device" is "On"
Following this, you may see duplicates of contacts in your iOS Address Book. This can be fixed by going into your iOS Address Book, pressing "Groups" and unchecking all groups except "All CircleBack".