Google Contacts - Google Contacts is Google's contact management tool that is available in its free email service Gmail, as a standalone service, and as a part of Google's business-oriented suite of web apps Google Apps.

FullContact Card Reader - Automagically scan biz cards into LinkedIn/Gmail contacts

SA Contacts Lite - SA Contacts Lite app comes up with features to help you in transferring all your contacts in your phone book between all your handheld devices without much of a stretch.

Truecaller - Find a person by a name or phone number worldwide for free using Truecaller.

Kontact - Kontact is the integrated Personal Information Manager of KDE.

Open Contacts - Open Contacts is an advanced address book program for managing contact info of individuals and...