[Jetpack] Mobile Theme Featured images on single views too

jp-single-thumb.php

<?php
/*
 * Plugin Name: Mobile Theme Featured images on single views too
 * Plugin URI: http://wordpress.org/extend/plugins/jetpack-mobile-theme-featured-images/
 * Description: Adds Featured Images before the content on the article pages, in Jetpack Mobile theme
 * Author: Jeremy Herve
 * Version: 1.0
 * Author URI: http://jeremyherve.com
 * License: GPL2+
 * Text Domain: jetpack
 */

// Check if we are on mobile
function matteholm_is_mobile() {

	// Are Jetpack Mobile functions available?
	if ( ! function_exists( 'jetpack_is_mobile' ) )
		return false;

	// Is Mobile theme showing?
	if ( isset( $_COOKIE['akm_mobile'] ) && $_COOKIE['akm_mobile'] == 'false' )
		return false;

	return jetpack_is_mobile();
}
 
// Let's add the post thumbnail, but only if we're on a mobile device and on a single page
function matteholm_maybe_add_filter() {

	// On mobile, and on an article page?
	if ( matteholm_is_mobile() && '1' == get_option( 'wp_mobile_featured_images' ) && is_single() )
		add_filter( 'the_content', 'jetpackme_single_featured_image' );

}
add_action( 'wp_head', 'matteholm_maybe_add_filter' );
 
// Build the function
function jetpackme_single_featured_image( $content ) {
	$featured_image = jeherve_single_thumb();

	if( is_admin() || !in_the_loop() )
		return $content;

	return $featured_image . $content;
}

function jeherve_single_thumb() { 
	global $post;

	if ( !$post )
		return;

	$post_id = $post->ID;
	$thumb = get_the_post_thumbnail( $post_id );

	echo '<div class="entry-thumbnail">' . $thumb . '</div><!-- .entry-thumbnail -->';
}