Our EVS Thumbnail API works over GET or POST it really doesn't matter There is actually a way of pulling all 10 thumbnails per video and also the splash image for each video via a url, one in standard form, and one in pretty.

evs-thumb-api.php

    			if(get_field('evs_oembed_video_url')) {
					$evs_location = get_option('evs_location');
					$api = $evs_location.'/api.php';

					$the_evs_page_url = get_field('evs_oembed_video_url');

					$video_thumb_info = wp_remote_post($api, array(
						'method' => 'POST',
						'timeout' => 45,
						'redirection' => 5,
						'httpversion' => '1.0',
						'blocking' => true,
						'headers' => array(),
						'cookies' => array(),
						'body' => array(
							'page_url' => $the_evs_page_url,
							'method' => 'public-file-images'
						)
					));
					$video_thumb_info = json_decode($video_thumb_info['body']);

					if(is_object($video_thumb_info) && $video_thumb_info->success == true) {
						$thumb = $video_thumb_info->thumbnail;

						echo '<img src='.$thumb.'>';

					}
				}

url-api-get-thumbs.php

Here is a "standard" url:
http://wphotline.com/evs/api.php?method=public-file-images&page_url=http://wphotline.com/evs/evs-vs-youtube-thumbnails-oembed-nonresponsive/

Here is the output from the above 'standard'url:

{"success":true,"splash":"http:\/\/evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com\/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-0.jpg","thumbnails":["http:\/\/evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com\/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-0.jpg","http:\/\/evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com\/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-1.jpg","http:\/\/evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com\/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-2.jpg","http:\/\/evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com\/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-3.jpg","http:\/\/evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com\/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-4.jpg","http:\/\/evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com\/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-5.jpg","http:\/\/evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com\/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-6.jpg","http:\/\/evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com\/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-7.jpg","http:\/\/evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com\/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-8.jpg","http:\/\/evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com\/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-9.jpg"],"thumbnail":"http:\/\/evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com\/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-0.jpg"}


Here is a 'pretty' url
http://wphotline.com/evs/api.php?responseType=pretty&method=public-file-images&page_url=http://wphotline.com/evs/evs-vs-youtube-thumbnails-oembed-nonresponsive/

Here is the output from the above 'pretty' url

Array
(
    [success] => 1
    [splash] => http://evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-0.jpg
    [thumbnails] => Array
        (
            [0] => http://evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-0.jpg
            [1] => http://evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-1.jpg
            [2] => http://evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-2.jpg
            [3] => http://evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-3.jpg
            [4] => http://evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-4.jpg
            [5] => http://evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-5.jpg
            [6] => http://evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-6.jpg
            [7] => http://evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-7.jpg
            [8] => http://evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-8.jpg
            [9] => http://evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-9.jpg
        )

    [thumbnail] => http://evp3-5100afa6ad386-8eb4309c974ba457b50745c630e3be0e.s3.amazonaws.com/EVS-vs.-Youtube-thumbnails--oEmbed-=-NonResponsive-thumbnail-0.jpg
)