AppRecs - AppRecs sorts through reviews in the App Store and automatically helps you filter out inauthentic results.
Cydia - An alternative app store for jailbroken devices.
JazzMyApp - Let JazzMyApp surprise you with amazing apps everyday. Try it out yourself.
Fnd - Browse Apple App Store and iTunes on the Web
FlekStore - Installing third party applications on iOS 9.
TheAppStore.org - Find apps by rating, price, category, updated date and more