Several PHP functions to get the +1 count from Google+ users for a given URL.

getGplusShares.php

<?php

// The original snippet from my SO answer here: http://stackoverflow.com/a/13385591/624466

/**
 * getGplusShares()
 *
 * Get the numeric, total count of +1s from Google+ users for a given URL.
 *
 * Example usage:
 * <code>
 *   $url = 'http://www.facebook.com/';
 *   printf("The URL '%s' received %s +1s from Google+ users.", $url, getGplusShares($url));
 * </code>
 *
 * @author          Stephan Schmitz <[email protected]>
 * @copyright       Copyright (c) 2013 Stephan Schmitz
 * @license         http://eyecatchup.mit-license.org/  MIT License
 * @link            <a href="https://gist.github.com/eyecatchup/8495140">Source</a>.
 * @link            <a href="http://stackoverflow.com/a/13385591/624466">Read more</a>.
 *
 * @param   $url    string  The URL to check the +1 count for.
 * @return  intval          The total count of +1s.
 */
function getGplusShares($url) {
    $url = sprintf('https://plusone.google.com/u/0/_/+1/fastbutton?url=%s', urlencode($url));
    preg_match_all('/{c: (.*?),/', file_get_contents($url), $match, PREG_SET_ORDER);
    return (1 === sizeof($match) && 2 === sizeof($match[0])) ? intval($match[0][1]) : 0;
}

GetPlusOnesByURL.php

<?php
/**
 * GetPlusOnesByURL()
 *
 * Get the numeric, total count of +1s from Google+ users for a given URL.
 *
 * Example usage:
 * <code>
 *   $url = 'http://www.facebook.com/';
 *   printf("The URL '%s' received %s +1s from Google+ users.", $url, GetPlusOnesByURL($url));
 * </code>
 *
 * @author          Stephan Schmitz <[email protected]>
 * @copyright       Copyright (c) 2014 Stephan Schmitz
 * @license         http://eyecatchup.mit-license.org/  MIT License
 * @link            <a href="https://gist.github.com/eyecatchup/8495140">Source</a>.
 * @link            <a href="http://stackoverflow.com/a/13385591/624466">Read more</a>.
 *
 * @param   $url    string  The URL to check the +1 count for.
 * @return  intval          The total count of +1s.
 */
function GetPlusOnesByURL($url) {
    !$url && die('No URL, no results. ;)');

    !filter_var($url, FILTER_VALIDATE_URL) &&
        die(sprintf('PHP said, "%s" is not a valid URL.', $url));

    foreach (array('apis', 'plusone') as $host) {
        $ch = curl_init(sprintf('https://%s.google.com/u/0/_/+1/fastbutton?url=%s',
                                      $host, urlencode($url)));
        curl_setopt_array($ch, array(
            CURLOPT_FOLLOWLOCATION => 1,
            CURLOPT_RETURNTRANSFER => 1,
            CURLOPT_SSL_VERIFYPEER => 0,
            CURLOPT_USERAGENT      => 'Mozilla/5.0 (Windows NT 6.1; WOW64) ' .
                                      'AppleWebKit/537.36 (KHTML, like Gecko) ' .
                                      'Chrome/32.0.1700.72 Safari/537.36' ));
        $response = curl_exec($ch);
        $curlinfo = curl_getinfo($ch);
        curl_close($ch);

        if (200 === $curlinfo['http_code'] && 0 < strlen($response)) { break 1; }
        $response = 0;
    }
    !$response && die("Requests to Google's server fail..?!");

    preg_match_all('/window\.__SSR\s\=\s\{c:\s(\d+?)\./', $response, $match, PREG_SET_ORDER);
    return (1 === sizeof($match) && 2 === sizeof($match[0])) ? intval($match[0][1]) : 0;
}

GetPlusOnesByURLRPC.php

<?php

// Alternative version using Google's internal (NOT MEANT FOR PUBLIC USE!) RPC API.

/**
 * GetPlusOnesByURLRPC()
 *
 * Get the numeric, total count of +1s from Google+ users for a given URL.
 *
 * Example usage:
 * <code>
 *   $url = 'http://www.facebook.com/';
 *   printf("The URL '%s' received %s +1s from Google+ users.", $url, GetPlusOnesByURLRPC($url));
 * </code>
 *
 * @author          Stephan Schmitz <[email protected]>
 * @copyright       Copyright (c) 2014 Stephan Schmitz
 * @license         http://eyecatchup.mit-license.org/  MIT License
 * @link            <a href="https://gist.github.com/eyecatchup/8495140">Source</a>.
 * @link            <a href="http://stackoverflow.com/a/13385591/624466">Read more</a>.
 *
 * @param   $url    string  The URL to check the +1 count for.
 * @return  intval          The total count of +1s.
 */
function GetPlusOnesByURLRPC($url) {
    !$url && die('No URL, no results. ;)');

    !filter_var($url, FILTER_VALIDATE_URL) &&
        die(sprintf('PHP said, "%s" is not a valid URL.', $url));

    $rpcRequest = '[{"method":"pos.plusones.get","id":"p","params":{"nolog":true,"id":"%s","source":"widget","userId":"@viewer","groupId":"@self"},"jsonrpc":"2.0","key":"p","apiVersion":"v1"}]';

    $ch = curl_init('https://clients6.google.com/rpc');
    curl_setopt_array($ch, array(
        CURLOPT_FOLLOWLOCATION => 1,
        CURLOPT_RETURNTRANSFER => 1,
        CURLOPT_SSL_VERIFYPEER => 0,
        CURLOPT_HTTPHEADER     => array('Content-type: application/json'),
        CURLOPT_POST           => 1,
        CURLOPT_POSTFIELDS     => sprintf($rpcRequest, $url),
    ));

    $response = curl_exec($ch);
    $curlinfo = curl_getinfo($ch);
    curl_close($ch);

    (200 !== $curlinfo['http_code']) && die(implode('; ', $curlinfo));

    $json = @json_decode($response, 1);
    return (!$json || !isset($json[0]['result'])) ? 0 : intval($json[0]['result']['metadata']['globalCounts']['count']);
}