public function notifyApp($app_id){
        $payload = array(
            'to' => $app_id,
            'sound' => 'default',
            'body' => "New Task Assigned"
        );

        $curl = curl_init();

        curl_setopt_array($curl, array(
        CURLOPT_URL => "https://exp.host/--/api/v2/push/send",
        CURLOPT_RETURNTRANSFER => true,
        CURLOPT_ENCODING => "",
        CURLOPT_MAXREDIRS => 10,
        CURLOPT_TIMEOUT => 30,
        CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
        CURLOPT_CUSTOMREQUEST => "POST",
        CURLOPT_POSTFIELDS => json_encode($payload),
        CURLOPT_HTTPHEADER => array(
            "Accept: application/json",
            "Accept-Encoding: gzip, deflate",
            "Content-Type: application/json",
            "cache-control: no-cache",
            "host: exp.host"
        ),
        ));

        $response = curl_exec($curl);
        $err = curl_error($curl);

        curl_close($curl);

        if ($err) {
        echo "cURL Error #:" . $err;
        } else {
        echo $response;
        }
    }