Contractbook - Helping businesses scale with future-proof contracts
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.
Concord - Contract Management Software and unlimited Electronic Signatures. Reduce costs, maximize compliance & mitigate risk. Enterprise solutions available.
Apple Contacts App - Access and edit your contacts from personal, business, and other accounts with the Contacts app.
Blitzen - Capture leads, manage contacts & automate your workflow
Windows Contacts - Windows has many extraordinary organizers, and in the event that you include distributed storage, then you presumably have more.