There are different versions of AFNetworking.
Latest AFNetworking 2.0 and higher requires Xcode 5, targeting either iOS
6.0 and above, or Mac OS 10.8 Mountain Lion (64-bit with modern Cocoa
runtime) and above.
For compatibility with iOS 5 or Mac OS X 10.7, use the 1.x release.
For compatibility with iOS 4.3 or Mac OS X 10.6, use the 0.10.x release.
Now if you want to support ios 4.3 or greater use 0.10 release.