The plugin enables you to add additional fields to the User profile page.
Adding those additional fields is a breeze. The problems come later.
It is not possible to retrieve those data using the function wp_get_current_user() or the global $current_user.
The plugin has NO documentation. And I stress NO documentation. The plugin appears to be an expedient by the author to collect payments (that he defines "donations") to obtain a full version of the plugin, or access to a some form of documentation about it. No problem in paying good money to good people. But done this way is *inelegant*, to be kind.