Cydia - An alternative app store for jailbroken devices.
Scoop - A command-line installer for Windows
JazzMyApp - Let JazzMyApp surprise you with amazing apps everyday. Try it out yourself.
Windows Remix - Web-based batch software installer with zero dependencies. Recommended first visit after reinstalling Windows or buying a new laptop.
Fnd - Browse Apple App Store and iTunes on the Web
Just Install - just-install - The stupid package installer for Windows.