Side Slider is a Joomla system plugin that loads any module inside and presents it after clicking the button. It can be excluded from the frontpage or any menu item using the menu ID. You can define colors for the button and the panel as well as specify right or left and distance from the top. You also can specify the text that appears on the button so as you can see this plugin is highly customizable. See all the parameters below.
This commercial plugin is included FREE with Vital.