RSPS List

http://www.toprsps.com/index.php?a=in&u=SiteName&ipc=IPtoCheck

Replace SiteName with the ID assigned to your website, and IPtoCheck with the user's IP.
The page will return 0 if the user has not voted today, and 1 if they have.

IP Check PHP Example

$result = file_get_contents("http://www.toprsps.com/index.php?a=in&u=SiteName&ipc=IPtoCheck");

if($result == 1) {

//User has voted in last 12H - reward the user
} else {

//This user hasn't actually voted, perhaps make a log about this.

} 

PHP Example

<?php
      #Example PHP Postback Script
      #Toprsps does not take responsibility or liability for the use of this php snippet

// Your Database Connection Details
$host = 'localhost';
$db_name = '';
$db_user = '';
$db_password = '';
mysql_connect($host, $db_user, $db_password);
mysql_select_db($db_name);

function _VoteReward($userId, $userIp, $valid) {

      if($valid == 1) {

            // Make userid safe to use in query
            $userId = mysql_real_escape_string($userId);

            // Check if that user votes already
            // Adjust this query to match your table name etc
            $voted = mysql_fetch_array(mysql_query("SELECT voted FROM vote_list WHERE user = '$userId'"));
            if(!$voted[0]) {
               // User has not voted, grant him reward, for example points
              mysql_query("UPDATE votepoints SET points = points+1 WHERE user = '$userId'");
            }
      }
}

//-------------------------- Don't change anything below this! -----------------------------
$Whitelist = array('198.143.128.25');

$userId = isset($_POST['userid']) ? $_POST['userid'] : null;
$userIp = isset($_POST['userip']) ? $_POST['userip'] : null;
$valid = isset($_POST['voted']) ? intval($_POST['voted']) : 0;
$at_refc = isset($_POST['at_refc']) ? $_POST['at_refc'] : null;

$result = false;
if (!empty($userId) && !empty($at_refc)) {

      if (in_array($at_refc, $Whitelist)) {
            $result = true;
            _VoteReward($userId, $userIp, $valid);
      }
}

if ($result) {
      echo 'OK';
}

//Close Connection
mysql_close();

?>