jiathis-home.php

<?php
/*
Plugin Name: Add JiaThis to the home page too
Version: 0.1
From http://wordpress.org/support/topic/add-content-under-post-on-main-page?replies=8
*/

add_filter( 'the_content', 'mh_jiathis' , 20 );

function mh_jiathis($content) {
        $jiathis_code = get_option('jiathis_code');
        $jiathis_dir = 'float:'.get_option('jiathis_dir');
        $jiathis_clear = '<div style="clear:both; margin-top:5px; margin-bottom:5px;"></div>';
    // if(is_single() || is_page() && get_option('jiathis_feed') == 'yes') {
    if( is_home() && get_option('jiathis_feed') == 'yes') {
                if(get_option('jiathis_pos') == 'down') {
                        $content = $content.$jiathis_clear."<div style=\"".$jiathis_dir."\">".$jiathis_code.'</div>'.$jiathis_clear;
                } else if(get_option('jiathis_pos') == 'up') {
                        $content = $jiathis_clear."<div style=\"".$jiathis_dir."\">".$jiathis_code.'</div>'.$jiathis_clear.$content;
                }
        }
        return $content;
}