Display WP Start bar on front page only

If you look at the plugin’s source, its main bits are hooked as following:

add_action('wp_enqueue_scripts', 'init_wpstartbar_files');
add_action('admin_print_scripts', 'init_wpstartbar_admin');
add_action('wp_footer', 'wpstartbar_footer',1);

The easiest way to conditionally disable it would probably be along (not tested):

add_action( 'template_redirect', function() {

if( ! is_front_page() ) {
    remove_action('wp_enqueue_scripts', 'init_wpstartbar_files');
    remove_action('admin_print_scripts', 'init_wpstartbar_admin');
    remove_action('wp_footer', 'wpstartbar_footer',1);
}

} );