WiseStamp - WiseStamp allows you to easily create and implement slick and unique email signatures for your business.
Ugly Email for FireFox - Get back your email privacy, block email tracking
Mailcastr - Create email signature that tells when your email is read.✉️
PixelBlock - Block email open tracking inside of Gmail
MySignature - MySignature is FREE Email Signature Generator that helps to create Professional Signatures for major email clients such as Outlook, Gmail...
Mailpanion - Track your email clicks & prevent others from tracking you.