title: what is correct format of bundle identifier in iOS?
body: <p>I have four bundle identifier </p>
  
  <ol>
  <li>com.company.appname</li>
  <li>com.appname</li>
  <li>appname</li>
  <li>com.company-name.app-name</li>
  </ol>
  
  <p>Please help me to find out correct bundle identifier,<br>
  Please tell me which is correct.</p>