FullContact
Freemium
FullContact gives you all the power of your address book, right in your Gmail inbox.
fruux
Freemium
fruux is a cross-platform synchronization service.
Memotoo
Commercial
Memotoo sync all your contacts from Gmail, Facebook, phone, Thunderbird, Outlook, etc in a single address book.
Compare Google Contacts with alternatives
Compare FullContact and Google Contacts and decide which is most suitable for you.
Compare Memotoo and Google Contacts and decide which is most suitable for you.
Compare fruux and Google Contacts and decide which is most suitable for you.