once fyi - Create privacy friendly one-time mailing lists

Crunchbase - Crunchbase is a platform for discovering industry trends, investments, and news about companies around the world.

Best Referral Programs - A curated directory of startup referral programs

CB Insights - CB Insights is a company database for the venture capital and corporate development community.

Viral Loops for Startups - Virality for startups made easy 💪

Tracxn - data on companies