ZabaSearch - Find people free with Zabasearch directory engine that includes free people search, reverse phone number lookup, address lookup, and more.

Clearbit - Clearbit provides Business Intelligence APIs

RealPeopleSearch - RealPeopleSearch is a web-based software that allows you to get the basic and public record of the concerned person within a few minutes by providing little information.

Memotoo - Memotoo allows you to sync your data (contacts, calendar, tasks, .) with phones (iPhone, Android, Samsung, ..

Numlooker - Numlooker is a web-based tool that is used to reverse the phone number that you have received.

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.