WiseStamp - WiseStamp allows you to easily create and implement slick and unique email signatures for your business.
Mailcastr - Create email signature that tells when your email is read.✉️
Ugly Email for FireFox - Get back your email privacy, block email tracking
Email Signature Template Generator - Create your free email signature with our easy-to-use tool.
PixelBlock - Block email open tracking inside of Gmail
MySigMail - UI email signature generator on GitHub