The AppSheet editor does provide automatic updates. Changes made by the user are automatically sent as they occur. Changes made by other users are retrieved by the editor every 30 minutes.
More details about automatic updates can be found here.
If you would like to turn off Automatic sync, go to the Behavior pane of the app editor and turn off Automatic updates. Also make sure that Delayed sync is turned on; this option only syncs the app when the user presses the sync button.