Cydia - An alternative app store for jailbroken devices.
iNoJB - iNoJB, formerly iNoCydia, is an amazing Cydia alternative requiring no jailbreak!
BuildStore - Safe and trustworthy alternative app store for iOS
Get Mods APK - Get Mods APK offers a big collection of new and top-rated Android Mod Games, Mod Games, Premium Tools that you can download without signing up.
Installer - Installer is a package manager build specifically for iOS. Older versions of Installer are Open Source
Apple App Store - Install apps on your iDevice via the App Store.