Get multisite themes being used

get_multisite_themes.php

if ( function_exists( 'get_sites' ) && class_exists( 'WP_Site_Query' ) ) {
	$sites = get_sites();
	foreach ( $sites as $site ) {
		switch_to_blog( $site->blog_id );
		$curr  = get_blog_details();
		$theme = wp_get_theme();
			echo '<h1>' . $curr->blogname . '</h1>';
			echo $theme->Name;

			$style_parent_theme = wp_get_theme(get_template());
			$style_parent_theme_author = $style_parent_theme->get( 'Author' );

			echo '<br>(' . $style_parent_theme->Name . ')';

		restore_current_blog();
	}
	return;
}