This plugin allows to automatically change the main MENU when a user logs in the website. So that  a different menu can be displayed for public users (guests) or for registered users (logged in).

Very simple to use:

1/ First of all, you have to design a different menu, and its associated module, for the logged in users.

2/ Once this is done you should have two menu modules. One to be displayed for guests, one to be displayed for registered users. Look at the module list and write dow the corresponding module ID numbers. 

3/ configure the plugin: give the IDs of the modules to be displayed for a guest and for a a registered user ( in the plugin parameters) .

4/ enable the plugin.