Security
ContactZapp writes to real address books, so it's treated as data-loss-critical throughout — from how merges are reviewed to how the data is stored.
Nothing writes back without review
Every merge is shown to you as a proposed record, built from the source fields it came from, before ContactZapp touches any connected account.
Every change is reversible
Merges are kept in a continuous history, not just a final state. If a merge turns out to be wrong, it can be rolled back.
Your contact data is encrypted per account
Contact data is encrypted with a key unique to your account, not a single shared key. No contact field is ever stored as plaintext.
Credentials are never exposed
Credentials for your connected accounts are used only to sync — they are never written to logs, exports or error messages.