Can I specify multiple endpoints for Sendgrid Event Notification?

Is it possible to configure send grid account, that I can specify multiple Post Event URL Event notification. Or maybe is it possible to add multiple Event Notification apps?

Currently there's no way to have the Events Webhook POST events to multiple URLs.

You could write a script that'd repost data to as many URLs as you wanted and direct SendGrid to POST to it. For example, written in in PHP:

// An array of the URLs you want to POST to:
$urls = array("http://mylocation1.com/event", "http://mylocation2.com/event");

$multi_handle = curl_multi_init();
$handles = array();
// Loop through each URL and create a cURL Handle for the URL
// The cURL handle will POST data that comes to this script to the url.
foreach ($urls as $key => $url) {
    $handles[$key] = curl_init();
    curl_setopt($handles[$key], CURLOPT_URL, $url);
    curl_setopt($handles[$key], CURLOPT_POST, 1);
    curl_setopt($handles[$key], CURLOPT_POSTFIELDS, $_POST);

    curl_setopt($handles[$key], CURLOPT_RETURNTRANSFER, true);
    curl_multi_add_handle($multi_handle, $handles[$key]);
}

$running = null;
// Run through each cURL handle and execute it.
do {
    curl_multi_exec($multi_handle, $running);
} while ($running);

curl_multi_close($multi_handle);

EDIT: It's now recommended that you use Reflector.io (another SendGrid Product) to have the webhook send to multiple destinations.