The following are notes for debug feature:
The "console" is a plugin now, so we need to add it by following command:
cordova plugin add https://git-wip-us.apache.org/repos/asf/cordova-plugin-console.git
And then you could use console API now, e.g.:
console.log('onSuccess! contacts.length:' + contacts.length );
You will see logs on output console of Xcode or Logcat of Eclipse.
Pls see following screenshots:

