Apollo.io

Apollo.io is a B2B sales platform that combines a huge database of company contacts with outreach tools. It's built by the company of the same name, which industry rankings place among the leaders in sales intelligence. It suits freelancers, agencies and entire sales teams that need to find the right people inside companies and reach out to them.

It works simply: you define who you're looking for — by job title, company size, industry or location — and Apollo filters a list of specific people including verified emails and phone numbers. From those contacts you then build an email sequence, schedule follow-ups and track who opened, clicked or replied.