This PHP file simply requires an online web server and some variables by you and it will show you the overall statistics of your repository.

github_download_counter.php

<?php

/*
 * GitHub Download Counter page
 * Created by Hendrik Erz <[email protected]>
 * Licensed via GNU GPL v3
 */

 // CONFIG
$repo = 'Zettlr/Zettlr'; // The repository
$highlight = '#3e6dd6'; // The highlight color for the page.

// Calculate a few things
$is_light = hexdec(substr($highlight, 1)) > 0xffffff * 0.5;
$contrast_strong = ($is_light) ? '#000' : '#fff';
$contrast_soft = ($is_light) ? '#444' : '#ddd';

// HELPER FUNCTIONS
function cURL ($url) {
  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL, $url);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);
  curl_setopt($ch, CURLOPT_CONNECTTIMEOUT,1);

  // GitHub requires a user agent header. So we'll just take something.
  curl_setopt($ch, CURLOPT_HTTPHEADER, array("User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/44.0.2403.89 Safari/537.36"));

  $result = curl_exec($ch);
  curl_close($ch);
  return $result;
}

function retrieveReleases ($repo) {
  $today = date('Y-m-d');
  $cache_file = "cache_$today.json";
  if (file_exists($cache_file)) {
    $cache = file_get_contents($cache_file);
    if ($cache !== false) {
      // Return the cache
      return json_decode($cache);
    }
  } else {
    // We will create the cache later on -- remove other cache files
    $files = scandir('.');
    if ($files !== false) {
      foreach ($files as $file) {
        if (preg_match('/cache_\d{4}-\d{2}-\d{2}\.json/', $file) === 1) {
          unlink($file);
        }
      }
    }
  }

  // First, let's grab some information on the repo!
  $curl_result = cURL("https://api.github.com/repos/" . $repo);
  if ($curl_result === false) {
    return false;
  }

  $repo_info = json_decode($curl_result);

  // Next on: The repo itself. NOTE: We will simply create a new array key for
  // the releases.
  // We have to account for the Github v3 pagination, which limits output to
  // 30 entries.
  $repo_info->all_releases = [];
  $page = 0;
  do {
    $page++;
    $releases = cURL("https://api.github.com/repos/" . $repo . "/releases?page=" . $page);
    if ($releases === false) {
      return false;
    }

    $releases = json_decode($releases);
    $repo_info->all_releases = array_merge($repo_info->all_releases, $releases);
  } while (sizeof($releases) > 0);

  // Cache the result
  $cache_contents = json_encode($repo_info);
  file_put_contents($cache_file, $cache_contents);

  // Return the cache
  return $repo_info;
}

// Helper function for delimiting numbers over 1.000 in output
function localise_number ($number) {
  if ($number < 1000) {
    return $number;
  }

  $delim = ',';
  $ret = (string) $number;
  $cnt = 0;
  for ($i = strlen($ret) - 1; $i > 0; $i--) {
    $cnt++;
    if ($cnt === 3) {
      $ret = substr($ret, 0, $i) . $delim . substr($ret, $i);
      $cnt = 0;
    }
  }

  return $ret;
}

function isWindowsExe ($filename) {
  return (
    str_ends_with($filename, '.exe') ||
    str_ends_with($filename, '.msi')
  );
}

function isMacOSApp ($filename) {
  return (
    str_ends_with($filename, '.dmg') ||
    str_ends_with($filename, '.pkg')
  );
}

function isLinuxExec ($filename) {
  return (
    str_ends_with($filename, '.deb') ||
    str_ends_with($filename, '.rpm') ||
    str_ends_with($filename, '.AppImage')
  );
}

function totalDownloadsPerPlatform ($releases) {
  $release_count = [
    'Windows' => 0,
    'macOS' => 0,
    'Linux' => 0,
    'Other Files' => 0,
  ];

  foreach($releases as $release) {
    foreach($release->assets as $asset) {
      if (isWindowsExe($asset->name)) {
        $release_count['Windows'] += $asset->download_count;
      } else if (isMacOSApp($asset->name)) {
        $release_count['macOS'] += $asset->download_count;
      } else if (isLinuxExec($asset->name)) {
        $release_count['Linux'] += $asset->download_count;
      } else {
        $release_count['Other Files'] += $asset->download_count;
      }
    }
  }

  return $release_count;
}

function readableKB ($kb) {
  $ret_val = $kb;
  $unit = 'KB';

  if ($ret_val > 1000) {
    $ret_val /= 1000;
    $unit = 'MB';
  }

  if ($ret_val > 1000) {
    $ret_val /= 1000;
    $unit = 'GB';
  }

  if ($ret_val > 1000) {
    $ret_val /= 1000;
    $unit = 'TB';
  }

  $ret_val = round($ret_val, 2);

  return "$ret_val $unit";
}

// Now, actually retrieve the releases
$repo_info = retrieveReleases($repo);
$downloads = totalDownloadsPerPlatform($repo_info->all_releases);

?>

<!DOCTYPE html>
<html lang="en" dir="ltr">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title><?php echo $repo_info->name; ?> Download Count</title>
  <style type="text/css">
  * {
    box-sizing:border-box;
  }

  html, body {
    margin:0;
    padding:0;
  }

  body {
    font-family: sans-serif;
    cursor:default;
  }

  h1, p {
    margin:0.5em;
    line-height: 120%;
  }

  a, a:visited, a:focus {
    color: <?php echo $highlight; ?>;
    text-decoration: none;
    transition:0.5s color ease;
  }

  a:hover {
    color: #999;
    transition:0.5s color ease;
  }

  footer {
    position: fixed;
    width: 100%;
    bottom: 0;
    background-color: <?php echo $highlight; ?>;
    color: <?php echo $contrast_strong; ?>;
    display: block;
    line-height: 200%;
    text-align: center;
  }

  footer a {
    color: <?php echo $contrast_soft; ?> !important;
  }

  div.container {
    width:100%;
  }

  @media (min-width:600px) { div.container { width: 80%; margin:0 auto; } }
  @media (min-width:800px) { div.container { width: 60%; margin:0 auto; } }
  @media (min-width:1000px) { div.container { width: 50%; margin:0 auto; } }
  @media (min-width:1200px) { div.container { width: 40%; margin:0 auto; } }

  table {
    border-collapse: collapse;
    width: 100%;
  }

  th, td {
    padding: 4px 20px;
    border-bottom: 1px solid #333;
  }

  td.number {
    text-align: right;
    padding-right: 20px;
  }

  td.filename {
    font-size: 80%;
    color: <?php echo $highlight; ?>;
  }

  td.divider {
    background-color: <?php echo $highlight; ?>;
    opacity: 0.2;
    border: none;
    border-bottom: 1px solid white;
    border-bottom-left-radius: 10px;
    border-bottom-right-radius: 10px;
  }

  tr {
    border-bottom: 1px solid #333;
  }

  tr:hover {
    background-color: #ddd;
  }

  span.date {
    font-style: italic;
    font-weight: normal;
    font-size: 75%;
  }

  a.topic-button {
    display: inline-block;
    margin: 5px;
    padding: 5px 10px;
    border-radius: 4px;
    background-color: <?php echo $highlight; ?>;
    color: <?php echo $contrast_strong; ?>;
    opacity: 0.8;
  }

  a.topic-button:hover {
    opacity: 1;
  }

  div#card-container {
    display: flex;
  }

  div.card {
    flex: 1 1 0px;
    padding: 10px;
    margin: 0 10px;
    border-radius: 10px;
    background-color: <?php echo $highlight; ?>;
    color: <?php echo $contrast_strong; ?>;
    text-align: center;
    font-weight: bold;
  }

  hr {
    margin: 20px 0px;
  }
  </style>
</head>
<body>
  <div class="container">
    <h1><?php echo $repo_info->name; ?> Download Count</h1>
    <p><em><?php echo $repo_info->description; ?></em> | <a href="<?php echo $repo_info->html_url; ?>" target="_blank">GitHub</a></p>
    <p>This page shows overall download counts for all versions of <?php echo $repo_info->name; ?>.</p>

    <div id="card-container">
      <div class="card">
        <p>Stargazers</p>
        <p><?php echo localise_number($repo_info->stargazers_count); ?></p>
      </div>

      <div class="card">
        <p>Forks</p>
        <p><?php echo localise_number($repo_info->forks_count); ?></p>
      </div>

      <div class="card">
        <p>Issues</p>
        <p><?php echo localise_number($repo_info->open_issues_count); ?></p>
      </div>

      <div class="card">
        <p>Repository Size</p>
        <p><?php echo readableKB($repo_info->size); ?></p>
      </div>
    </div>

    <hr>

    <p>
      <?php
      foreach ($repo_info->topics as $topic) {
        echo "<a href=\"https://github.com/topics/$topic\" class=\"topic-button\" target=\"_blank\">$topic</a>";
      }
      ?>
    </p>

    <h2>At a Glance</h2>
    <p>
      <table>
        <thead>
          <tr>
            <th style="text-align: left;">Platform</th>
            <th style="text-align: right;">Total Download Count</th>
          </tr>
        </thead>
        <tbody>
        <?php
          $total = 0;
          foreach ($downloads as $platform => $count) {
            $total += $count;
            echo "<tr><td>$platform</td><td class=\"number\">" . localise_number($count) . "</td></tr>";
          }

          echo "<tr><th style=\"text-align: left;\">Total downloads:</th><th style=\"text-align: right;\">" . localise_number($total) . "</th></tr>";
        ?>
        </tbody>
      </table>
    </p>

    <p>&nbsp;</p>

    <?php

    // Additional info: How many days since the first release?
    $firstRelease = array_reverse($repo_info->all_releases)[0]; // Last index = first release
    // Get Unix seconds
    $firstRelease = strtotime($firstRelease->published_at);

    $daysSinceFirstRelease = round((time() - $firstRelease) / 60 / 60 / 24);
    $yearsSinceFirstRelease = floor($daysSinceFirstRelease / 365);
    $downloadsPerDay = round($total / $daysSinceFirstRelease);

    echo "<p>All <strong>" . localise_number(sizeof($repo_info->all_releases)) . "</strong> releases of $repo_info->name have been downloaded <strong>" . localise_number($total) . "</strong> times.</p>\n";
    echo "<p>The first release was made <strong>";
    if ($yearsSinceFirstRelease > 0) {
      echo "$yearsSinceFirstRelease years and " . ($daysSinceFirstRelease % 365) . " days";
    } else {
      echo $daysSinceFirstRelease . " days";
    }
    echo "</strong> ago. On average, $repo_info->name is downloaded <strong>$downloadsPerDay times each day</strong>.</p>";
    ?>
    <p>&nbsp;</p>
    
    <h2>In Detail</h2>

    <?php

    // Now generate.
    echo "<table>\n<tr><th>Release</th><th style=\"text-align: left;\">Platform</th><th style=\"text-align: right;\">Downloads</th></tr>\n";
    // First: Loop through all releases
    foreach($repo_info->all_releases as $release) {
      echo "<tr><th rowspan=\"" . (count($release->assets)+1) . "\">$release->tag_name<br><span class=\"date\">" . date("M d, Y, H:i", strtotime($release->published_at)) ."</span></th></tr>\n";
      // Sort the assets
      usort($release->assets, fn($a, $b) => $b->download_count - $a->download_count);
      // Then loop through all assets ...
      foreach($release->assets as $asset) {
          echo "<tr><td title=\"$asset->name\" class=\"filename\">$asset->name</td><td class=\"number\">" . localise_number($asset->download_count) . "</td></tr>\n";
        }

      // Everytime add a spacer row
      echo "<tr><td class=\"divider\" colspan=\"3\"></td></tr>";
    }
    echo "</table>\n";

    ?>
    <div style="margin-bottom: 20%;">&nbsp;</div>
  </div>
  <footer>
    GitHub Download Counter | Copyright &copy; 2018&mdash;<?php echo date("Y") ?> Hendrik Erz | License: <a href="https://www.gnu.org/licenses/gpl-3.0.en.html" target="_blank">GNU GPL v3</a> | <a href="https://gist.github.com/nathanlesage" target="_blank">Download at GitHub Gist</a>
  </footer>
</body>
</html>