EmailTrackerPro - EmailTrackerPro is an email tracking and spam filter solution.
Strike - Share your experience and hold businesses accountable 👊
ReadNotify - ReadNotify enables the user to know when email is sent and the reciever reads the email.
dip - accountability groups for developers
Sendia - Send cold email in seconds with Sendia, an outreach tool for Gmail that's free & easy to use!
Rainmaker - Rainmaker allows you to make your Google Contacts better.