Covve is designed to seamlessly sync 2 way with your entire phone’s address book, and will support contacts that come from all major contact accounts (Google Contacts, Exchange, iCloud, Outlook, and Yahoo).
Most data updated using Covve, is also automatically synced back to your phone's address book - so data added by Covve is yours to keep.
See here what data is synced back:
Note: Covve-specific data, such as 'Industry', reminders and activity notes, are not synced back to your address book as they cannot be matched to the native phone addressbook.
In general, Covve will synchronize with your address book every few seconds while you're online.