The plugin notifies the comment author via email when someone replies to his/her comment. The current features of this plugin:
You’re able to customize reply, re-notify and modification email templates. Copy the plugin’s “templates” folder to your theme folder & set your own design. The plugin will look for templates on the “/wp-content/themes/[THEME_DIR]/templates/” folder. If you want to use default templates, then you don’t need to do this thing.