Simplexml get attributes with a namespace
You need to use the namespace when getting the attribute. The android namespace is defined as:
http://schemas.android.com/apk/res/android
So you need to pass that to the attributes() method, like this:
$xml = simplexml_load_string($xmlStr);
echo (string) $xml->application->activity->attributes('http://schemas.android.com/apk/res/android')->name;
Outputs
com.sunil.tweet.MainActivity
Codepad Demo