Atto’s slowly been gaining functionality through plugins released at Moodle.org. The newest plugin provides a familiar fullscreen option to help with editing a lot of html to give you self a larger canvas when editing a page that might be displayed full width of user screens as well. The plugin is maintained by Daniel Thies.
This brings the total approved Atto plugins to 15 and counting.
Download it for Moodle 2.7 or 2.8: https://moodle.org/plugins/view.php?plugin=atto_fullscreen