WP Vegas uses Jay Salvat's vegas.js to display large background image slideshows. This plugin can be used to add a single fullscreen background image to a WordPress website or an album of awesome slides. I've tried to make it as easy as possible to manage your fullscreen slideshows.
WP Pace allows you to easily add customizable loading bars and other loading animations to your WordPress website. This plugin makes use of pace.js which is an awesome script with no jQuery dependancies. There's very minimal setup, you just have to choose the style and color you want and you're good to go.