When someone comes to your site, it will welcome them as a guest and offer them to register or login.
When the customer is logged in, it welcomes them back with there first and last name.
This also changes the account page by adding icons and making it look processional and easier on the eyes.
This should work with just about any theme so long the header file and account files are the same as the default.
If for some reason it dose not work with your theme, let me know and I will give you an e-mail address to send these 2 files to and I will adjust this mode to work for your theme.