The final result from hours of googling, finally I can find this snippet.

SimplePhpFlickr.php

<?php
	// Read more API Documentation @ https://www.flickr.com/services/api/
	$xml = simplexml_load_file("https://api.flickr.com/services/rest/?method=flickr.people.getPublicPhotos&user_id={YOUR USER ID}&per_page=[NUMBER OF PHOTOS TO FETCH]&api_key={REQUIRED!!! YOUR API KEY}&&format=rest");
	$output = "<div>";
	foreach($xml->children()->children() as $child) {
		$imgsrc = "http://farm" . $child['farm'] . ".static.flickr.com/" . $child['server']. "/" . $child['id'] . "_" . $child['secret'] . "_s.jpg"; // More about image size suffixes: https://www.flickr.com/services/api/misc.urls.html
		$fullsize = "http://farm" . $child['farm'] . ".static.flickr.com/" . $child['server']. "/" . $child['id'] . "_" . $child['secret'] . "_o.(jpg|gif|png)";
		$output .= "<a href='".$imgsrc."'>";
		$output .= "<img src='".$imgsrc."' />";
		$output .= "</a>";
	}
	$output .= "</div>";
	echo ($output);