title: This App Is Incompatible With This iPod touch
body: <p>I have developed an app that required iOS >= 4.0. But when I download it from App Store by using my iPod touch 2 (iOS 4.2.1), it says "This App Is Incompatible With This iPod touch". I don't know why. And when I use this iPod touch to run the app through Xcode, it also don't run on my iPod touch. How can I debug this error?</p>
  
  <p>I have read <a href="https://stackoverflow.com/questions/8218679/why-does-my-ios-app-not-run-on-my-ipod-touch">this</a> and my app build settings show that "Architectures" is "Standard(armv7)" and "Valid Architectures" is "armv6 armv7", I wondered if it's wrong.</p>