$html = file_get_contents('https://play.google.com/store/search?q=war+games&c=apps');
preg_match_all("/data-docid="([^"]*)"/i", $html, $data);

$list = array_keys(array_flip($data[1]));
$packageNameToSearchFor = 'com.lighting.commander';

if (in_array($packageNameToSearchFor, $list)) {
    $order = array_search($packageNameToSearchFor, $list)+1;

    echo 'Position: '.$order;
} else {
    echo 'Not found!';
}