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

PitchWall - Browse new startups, and submit your mobile app/games startup's beta page here.

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

Product Hunt - A website that lets users share and discover new products

Tracxn - data on companies

SimilarPages.com - SimilarPages has found and classified millions of interesting sites hidden due to low popularity with the goal of helping you discover and search a larger portion of the web