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.
Product Hunt - A website that lets users share and discover new products
Free Software Directory - The Free Software Directory is a project of the Free Software Foundation (FSF) and United Nations...
Filehippo - Filehippo is your key to opening files that Windows claims are "in use by another user" or simply "can't be found." Avoid the hassle.
Alternative.me - Welcome to alternative.me, the source of better software alternatives. Finding suitable software was never easier.
Slant.co - Slant is a collaboratively edited resource that helps you quickly make decisions.