He gives you a browser link you can click on any website to get javascript debugging tools.
Storager provides local and session storage viewing, It also allows you to export to jdrop website to inspect contents remotely, which is great for debugging local storage on mobile devices.
This plugin extends Firebug to give you the functionality you need. As with Firebug itself, FireStorage Plus! is currently under heavy development so new features come out every couple of days...