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
Top Similar Sites - Top Similar Sites helps you find similar, alternative or related sites to any website instantly.
Free Software Directory - The Free Software Directory is a project of the Free Software Foundation (FSF) and United Nations...
SimilarSites - Easily find more sites like those you like.
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.