Facebook app lost 100% of their iOS dev team when joe hewitt stopped developing for them. They decided to let interns in charge of native libraries like Three20 (which has become a mess since then) and let web people in charge. It took them to hire someone from Apple to get their things together and do something valid on that platform. What's crazy is that nobody around them was able to tell them that mobile constraints makes it a entirely different think than the web. You just need to code one "hello world" with one button using phonegap to realize that uiwebview isn't anywhere close to native sdk. On the other side,the fact that Apple decided not to update UIWebView to nitro was probably a big matter for them...