Defer the loading of all javascripts added with wp_enqueue_scripts, using LABJS (an asynchronous javascript library).
This plugin defer the loading of all javascripts added by the way of wp_enqueue_scripts, using LABJS. The result is a significant optimization of loading time.
It is compatible with all WordPress javascript functions (localize_script, js in header, in footer ...) and works with all well coded plugins.
If a plugin or a theme is not poperly enqueuing scripts, your site may not work. Check this page : Function Reference/wp_enqueue_script on WordPress Codex
LABjs (Loading And Blocking JavaScript) is an open-source (MIT license) project supported by Getify Solutions.
We performed a range of tests to determine the potential benefit of loading time. On wabeo we executed webwait (150 calls by test). Result is this plugin could improve your loading time by 25% !! More information in the Screenshots section.
You can find more information about WP defered Javascripts and technical information about asynchronous scripts on authors blogs.