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

Looker - Looker makes it easy for analysts to create and curate custom data experiences—so everyone in the business can explore the data that matters to them, in the context that makes it truly meaningful.

ReadNotify - ReadNotify enables the user to know when email is sent and the reciever reads the email.

Clari - Clari is a predictive analytics platform for sales people.

Bananatag - Find out what happens to your emails after you press send! Add email tracking, attachment tracking, email scheduling and templates to your daily emails.

Sisense - The BI & Dashboard Software to handle multiple, large data sets.