Flashissue Tracker integrates with your gmail account to allow you to track opens for emails sent via your Gmail. It's great for everyday use when you’re sending email to clients or prospects and it helps you learn how people interact with your emails.
The tracking feature is automatically turned on when you enter your Gmail account but it can be turned on/off from the the Gmail Compose window. You can view opens from your Gmail Inbox or Sent folders.
Tracking labels are color coded:
Every Thread has been Opened
Some Threads have been Opened