To build working iOS apps quickly and painlessly I have often leveraged open source libraries. It’s important to avoid reinventing the wheel every time your app needs to hit the network, use common UI, socially share content, etc.
People have listed libraries before (here, here, and here), I wanted to highlight some that lean more towards dev tools than front facing user features
read more- http://tech.xtremelabs.com/ios-libraries-for-productive-programming/