Campaign Genius - Send dynamic email content through any platform, instantly.
Strike - Share your experience and hold businesses accountable 👊
GMass - GMass allows you to easily schedule emails, send out mass emails and mail merge campaigns and more with Gmail! Click here to learn about more features!
dip - accountability groups for developers
MailChimp Snap - Send simple, photo-based email campaigns from your phone.
Rainmaker - Rainmaker allows you to make your Google Contacts better.