Hunter - Find all the email addresses related to a domain

Capterra - Capterra helps millions of people find the best business software. With software reviews, ratings, infographics, and the most comprehensive list of the top business software products available, you're sure to find what you need at Capterra.

Apollo.io - Apollo’s predictive prospecting, sales engagement, and actionable analytics help the teams to reach its full revenue potential.

AlternativeTo - AlternativeTo lets you find apps and software for Windows, Mac, Linux, iPhone, iPad, Android, Android Tablets, Web Apps, Online, Windows Tablets and more by recommending alternatives to apps you already know.

Icypeas - This email finder has the capacity to bypass catch-alls

SaaSHub - Find and promote software that will help you grow your business or to be more productive.