WiseStamp - WiseStamp allows you to easily create and implement slick and unique email signatures for your business.
Clearbit - Clearbit provides Business Intelligence APIs
MySignature - MySignature is FREE Email Signature Generator that helps to create Professional Signatures for major email clients such as Outlook, Gmail...
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.
Sigstr - Email signature marketing
InsideView - InsideView aggregates and curates all the company and contact data, news and social insights, and professional connections you need to do business better.