WordPress at a glance
filter is not described

wp_is_mobile filter-hook . WP 4.9.0

Filters whether the request should be treated as coming from a mobile device or not.

Usage

add_filter( 'wp_is_mobile', 'filter_function_name_8359' );
function filter_function_name_8359( $is_mobile ){
	// filter...

	return $is_mobile;
}
$is_mobile(true/false)
Whether the request is from a mobile device or not.

Where the hook is called

wp_is_mobile()
wp-includes/vars.php 149
return apply_filters( 'wp_is_mobile', $is_mobile );

Where the hook is used (in WP core)

Does not used.