Lusha is a continuously updating database that provides B2B Salespeople with targeted, accurate, and timely business information. Lusha aggregates its data from multiple sources, cross-checking and updating LIVE to ensure up-to-the-minute data accuracy and database cleanliness.
Mailtrack.io - The best email tracking solution I've found. Free
Hunter - Find all the email addresses related to a domain
ReadNotify - ReadNotify enables the user to know when email is sent and the reciever reads the email.
Apollo.io - Apollo’s predictive prospecting, sales engagement, and actionable analytics help the teams to reach its full revenue potential.
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.
ZoomInfo - ZoomInfo is a B2B database providing detailed business information on people and companies.