Albacross - The world's first free B2B Lead Generation Network. Albacross help companies master their B2B digital marketing with Lead Generation and targeted marketing
fruux - Free service that takes care of your contacts, calendars and more so you don't have to.
Hunter - Find all the email addresses related to a domain
FullContact - Put the power of full contact information into your web or mobile apps.
Upscribe - Embeddable lead generation forms for Medium
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.