Zeetaminds - Zeetaminds offers cloud based digital signage software with live social media integration. 

Unlimited Email Tracker - Track opens and clicks, set reminders and delays in Gmail

ScreenCloud - ScreenCloud is a simple, cloud-based Digital Signage software solution that makes it easy to display video, images and content on screens.

EmailTrackerPro - EmailTrackerPro is an email tracking and spam filter solution.

Embed Signage - Multi-platform Digital Signage Software that's quick to learn and powerful to use. Packed with features, simple to use and wide range of device platform support. A better way to manage your Digital Signage.

Mailtrack.io - The best email tracking solution I've found. Free